EMC PowerPath for Linux Version 5.3 Service Pack · PDF filePowerPath operates on Red Hat Enterprise Linux (RHEL), SuSE Linux Enterprise Server ... Support for Encryption in a Veritas

These release notes contain information about features, systemrequirements, and limitations in PowerPath Version 5.3 and ServicePack releases for Linux.

◆ Revision History ................................................................................... 2◆ Product description.............................................................................. 2◆ New features and changes .................................................................. 3◆ Fixed problems ................................................................................... 10◆ Environment and system requirements.......................................... 11◆ Known problems and limitations .................................................... 21◆ Technical notes.................................................................................... 33◆ Documentation ................................................................................... 44◆ Software media, organization, and files.......................................... 46◆ Installation........................................................................................... 48◆ Troubleshooting and getting help.................................................... 49

EMC® PowerPath®

for LinuxVersion 5.3 and Service Pack and Patch Releases

Release NotesP/N 300-008-345

Rev A06

December 21, 2009

1

2

Revision History

Revision HistoryThe following table presents the revision history of this document.

Product descriptionThe EMC® PowerPath® family of products includes PowerPathmultipathing software, PowerPath Migration Enabler®, andPowerPath Encryption with RSA®.

PowerPath is a server-resident software solution designed to enhanceperformance and application availability. PowerPath combinesautomatic load balancing, path failover, and multiple path I/Ocapabilities into one integrated package.

PowerPath operates on Red Hat Enterprise Linux (RHEL), SuSELinux Enterprise Server (SLES), Oracle Enterprise Linux (OEL), andAsianux servers connected to EMC and third-party storage systemsin stand-alone and clustered configurations as detailed inenvironment and system requirements. PowerPath supports FibreChannel and iSCSI environments.

Your license type determines the extent of PowerPath functionalityavailable. If you have questions about your license, contact your EMCCustomer Support Representative.

Revision Date Description

A01 March 10, 2009 First release of PowerPath Version 5.3 and ServicePack Releases Release Notes.

A02 August 21, 2009 Release of PowerPath Version 5.3 SP2

A03 September 3, 2009 Added support for CLARiiON FLARE 04.29; VxVM,VxFS, and VCS with version 5.0RU1; Xen kernels;and the procedure to change device mapperdependency to pseudo devices (SLES 11).

A04 September 28, 2009 Release of PowerPath Version 5.3 SP1.

A05 October 7, 2009 Added PowerPath Version 5.3 SP1 support forRHEL 5.4.

A06 December 21, 2009 Release of PowerPath Version 5.3 SP1 Patch01

EMC PowerPath for Linux Version 5.3 and Service Pack Releases Release Notes

New features and changes

New features and changesThis section includes new features and changes in PowerPath Version5.3 and service pack releases.

PowerPath 5.3 SP1 P01PowerPath version 5.3 SP1 Patch 01 (P01) for Linux is a limitedfunctionality service pack that is supported only with SLES 10 SP3.No other Linux Kernels are supported. Additionally, PowerPath 5.3SP1 P01 does not support PowerPath Encryption with RSA.PowerPath will support these features with SLES 10 SP3 in a futurePowerPath release, as yet to be determined.

Note: Do not upgrade to PowerPath version 5.3 SP1 P01 unless you alreadyhave SLES 10 SP3 running on the host where you want to install PowerPath.

PowerPath version 5.3 SP1 P01 for Linux is a full package installation.

PowerPath version 5.3 SP1 P01 includes support for the followingfeatures:

◆ Support for SLES 10 SP3 only. The Linux operating systemssupported in earlier versions of PowerPath will not be supportedin version 5.3 SP1 P01.

◆ Support for PowerPath Migration Enabler.

PowerPath 5.3 SP1PowerPath Version 5.3 SP1 for Linux is a full package installation. Toupgrade to PowerPath Version 5.3 SP1, refer to the EMC PowerPath forLinux Installation and Administration Guide.

PowerPath Version 5.3 SP1 for Linux adds support for the followingnew features:

◆ Support for PowerPath Migration Enabler technologiesincluding:

• Thin target LUNs for EMC Symmetrix® and CLARiiONarrays.

• Solutions Enabler remote client with the Open Replicator (OR)and TimeFinder/Clone (symclone) technology types.

3EMC PowerPath for Linux Version 5.3 and Service Pack Releases Release Notes

4


The EMC PowerPath Migration Enabler User Guide provides moreinformation.

◆ Support for CLARiiON FLARE version 04.29, which includessupport for more than 256 LUNs per Storage Group.

◆ Support for Encryption in a Veritas Cluster Server (VCS) 4.1 and5.0 cluster environment for SLES9 SP4 x86_64 andRHEL4.x x86_64 only.

◆ Support for the PP_DISPLAY_TIME_STAMP environmentvariable which adds a time stamp to the powermt displaycommand output when either the TIME_VERBOSE orTIME_SECONDS time display format is defined. Refer to“PP_DISPLAY_TIME_STAMP environment variables” on page 37and to the EMC PowerPath Family CLI and System MessagesReference Guide for more information.

◆ Support for Symmetrix V-MAX R1/R2.

◆ Support for FCoE.

◆ Support for 8GB HBA.

◆ Support for the following kernels:

• RHEL 4.8, 5.4

• Asianux 3.0 SP2

• Oracle Enterprise Linux 4.8

Refer to “Kernel support” on page 13 for all supported kernels.

◆ Several bug fixes, as described in “Fixed problems” on page 10.

Changed features For PowerPath Version 5.3 SP1 and later, the range of valid latencythreshold values has been changed to 0 to 3600. When the value is setto zero (0), this is called "Discovery Mode." In Discovery Mode,PowerPath logs every subsequent threshold cross to provide a viewof the latency in your environment and an idea of an appropriatethreshold value setting.

End-of-life announcementsPowerPath Version 5.3 SP1 has the following end-of-lifeannouncements:

◆ PowerPath Migration Enabler 5.3 SP1 for Linux is the last versionto support native-to-native and native-to-pseudo migrations.



◆ EMC is phasing out PowerPath support for HP StorageWorksEVA 3000/5000 arrays with firmware VCS 3.x, HP StorageWorksXP 48/128/512/1024 arrays, and Hitachi Lightning arrays.PowerPath Version 5.3.x is the last version for Linux to includequalified support for these arrays, and subsequent releases willnot support them. Earlier PowerPath for Linux versions willcontinue to support the arrays in accordance with the EMCsoftware support duration policy. EMC strives to minimizecustomer impact when implementing support changes and tomaintain backward compatibility whenever possible.

PowerPath 5.3 SP2

Note: PowerPath 5.3 SP2 for Linux is also known as PowerPath for Linux version5.3.2 for SLES 11 on Powerlink. Version 5.3 SP2 and 5.3.2 are equivalent.

PowerPath Version 5.3 SP2 for Linux is a limited functionality servicepack that is supported only with SLES 11. No other Linux kernels aresupported. Additionally, PowerPath 5.3 SP2 does not supportPowerPath Migration Enabler or PowerPath Encryption with RSA.PowerPath will support these features with SLES 11 in a futurePowerPath release, as yet to be determined.

Note: Do not upgrade to PowerPath Version 5.3 SP2 unless you already haveSLES 11 running on the host where you want to install PowerPath.

PowerPath Version 5.3 SP2 for Linux is a full package installation. Toupgrade to PowerPath Version 5.3 SP2, upgrade to SLES 11 and thenupgrade to PowerPath Version 5.3 SP2 as described in the EMCPowerPath for Linux Installation and Administration Guide.

PowerPath Version 5.3 SP2 includes support for the followingfeatures:

◆ Support for SLES 11 only. The Linux Operating Systemssupported in earlier versions of PowerPath will not be supportedin Version 5.3 SP2.

◆ Support for CLARiiON® FLARE® version 04.29, which includessupport for more than 256 LUNs per Storage Group.

◆ Support for the PP_DISPLAY_TIME_STAMP environmentvariable which adds a time stamp to the powermt displaycommand output when either the TIME_VERBOSE or


6


TIME_SECONDS time display format is defined. Refer to“PP_DISPLAY_TIME_STAMP environment variables” on page 37and to the EMC PowerPath Family CLI and System MessagesReference Guide for more information.

◆ Support for Symmetrix V-MAX storage arrays.

◆ Support for FCoE.

◆ Support for iSCSI on PowerPC (PPC64).

◆ Support for SteelEye LifeKeeper High Availability Clusteringversion 7.xx on SLES 11.

◆ Support for Veritas Volume Manager (VxVM), Veritas File System(VxFS), and Veritas Cluster Server (VCS) with version 5.0RU1 forSymmetrix and CLARiiON storage arrays. Third-party arrays arenot qualified as Symantec does not provide pseudo name supportand PowerPath 5.3 SP2 does not provide native device support.


Changed features The range of valid latency threshold values has been changed to 0 to3600. When the value is set to zero (0), this is called "DiscoveryMode." In Discovery Mode, PowerPath logs every subsequentthreshold cross to provide a view of the latency in your environmentand an idea of an appropriate threshold value setting.

PowerPath 5.3PowerPath Version 5.3 for Linux is a full package installation. Toupgrade to PowerPath Version 5.3, refer to the EMC PowerPath forLinux Installation and Administration Guide

PowerPath Version 5.3 for Linux adds support for the following newfeatures:

◆ Enhancement of the emcpadm command to export and importpseudo device name and logical unit data in XML format. Refer to“emcpadm enhancements” on page 37 and the EMC PowerPathFamily CLI and System Messages Reference Guide for moreinformation.

◆ Support for the PowerPath Management Daemon using SNMPthat monitors the device path status and reports the event whenthe path is dead or all paths to the volume are dead based on theconfiguration file. “Management Daemon using SNMP” on



page 37 and the EMC PowerPath for Linux Installation andAdministration Guide has more information on the PowerPathManagement Daemon using SNMP.

◆ Support for IBM Power (IBM PPC) on RHEL 5.2, RHEL 5.3, andSLES 10 SP2, a feature that allows PowerPath with Linux to runon PowerPC (PPC64) hardware. “IBM PowerPC support” onpage 38 contains more information on IBM PPC.

◆ Support for PowerPath Encryption with RSA software.“PowerPath Encryption with RSA software” on page 9 providesadditional information.

◆ Support for PowerPath Migration Enabler technologiesincluding:

• New Migration Enabler TimeFinder/Clone function thatcreates a full volume copy of a source device within the sameEMC Symmetrix array.

• Invista encapsulation of the source device name when usingMigration Enabler with EMC Invista® Versions 2.1 and 2.2.

• A host-based copy (also known as host copy) function thatmigrates data, in conjunction with the host operating system,from the specified source logical unit to the target logical unit.

The EMC PowerPath Migration Enabler User Guide provides moreinformation.

◆ Support for logging has been expanded to generate auditmessages on most powermt PowerPath commands. Runningthese commands generate audit messages that allow users totrack commands run on a particular host. The EMC PowerPath forLinux Installation and Administration Guide and the EMC PowerPathFamily CLI and System Messages Reference Guide contain moreinformation on audit logging.

◆ Support for security root check has been added to variouspowermt, powermig, and powervt PowerPath commands.Security root check allows administrators to restrict access toprivileged users.

◆ Path latency monitoring has been updated to reset the pathlatency threshold value to 0 (zero) when latency monitoring isturned off. When powermt set path_latency_monitoring=off isrun, the path latency threshold value resets to 0.


8


◆ Support for SteelEye LifeKeeper High Availability Clusteringversion 6.xx on RHEL 4.6, RHEL 5.1, SLES 9 SP4, and SLES 10SP1.

◆ Support for the following kernels:

• RHEL 5.3

• SLES 10 SP2

• Asianux 3.0 SP1

• Oracle Enterprise Linux version 5.2

Refer to “Kernel support” on page 13 for all supported kernels.


Changed features When new devices are added to or removed from the host, theconfiguration changes. Any change in the device configuration in thehost requires you to carry out an explicit powermt save to save thechanged configuration.



PowerPath Encryption with RSA softwarePowerPath Version 5.3 introduces support for PowerPath Encryptionwith RSA software. PowerPath Encryption with RSA is host-basedsoftware distributed as part of the PowerPath Version 5.3 package.However, a separate product license is needed to use PowerPathEncryption.

The following documents, available on the Powerlink website,contain more information about PowerPath Encryption with RSA:

◆ EMC PowerPath Encryption with RSA User Guide

◆ EMC PowerPath Encryption with RSA Release Notes

End-of-life announcementsEMC is phasing out PowerPath support for HP StorageWorksEMA12000, EMA16000, and MA8000 arrays. PowerPath Version 5.3 isthe last version for Linux to include qualified support for thesearrays, and subsequent releases will not support them. EarlierPowerPath for Linux versions will continue to support the arrays inaccordance with the EMC software support duration policy. EMCstrives to minimize customer impact when implementing supportchanges and to maintain backward compatibility whenever possible.


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Fixed problems

Fixed problemsThis section lists the fixed problems in PowerPath Version 5.3. Youcan view the most current fixed problems for PowerPath online usingEMC E-Lab™ Issue Tracker on EMC Powerlink®. “Troubleshootingand getting help” on page 49 provides additional information onaccessing Issue Tracker.

Table 1 Fixed problems in PowerPath Version 5.3 and service pack releasesfor Linux (1 of 2)

DescriptionFound inversion

Fixed inversion

307645PowerPath Version 5.3 will not start when the largesmp kernel is used due to a regularexpression syntax error in the PowerPath startup script.This issue is also documented in EMC Knowledgebase Solution emc212938.

5.3 5.3 SP1

288561Dynamic addition of large number of LUNs may result in a host hang.

5.1 SP2 5.3

286140Starting PowerPath 5.1 SP2 after upgrading from PowerPath 4.5.3 gives the following error:Starting PowerPath: WARNING: Can't read module

/lib/modules/2.6.9-78.ELsmp/weak-updates/emcplib.ko: Nosuch file or directory

This issue is also documented in EMC Knowledgebase Solution emc196281.

5.1 SP2 5.3

285558Segfault message is logged in the messages file when PowerPath is started on a SLES 9 SP4x86_64 host running PowerPath 5.1 SP2.

5.1 SP2 5.3

285242Oracle ASM (Automatic Storage Management) is not able to use emcpower devices to mark aLUN as an ASMLib volume.This issue is also documented in EMC Knowledgebase Solution emc203137.

5.1 SP1 5.3 SP1

283816After disabling HBA1 on systems running PowerPath 5.1 SP2 with SLES 10 SP2, PP_inqoutputs junk characters. PP_inq works fine with both HBAs active.

5.1 SP2 5.3

264869With PowerPath service stopped, ’powermt asdf’ gives "Error: unable to update deviceconfiguration file(s)", instead of printing the usage.

5.1 5.3


Environment and system requirements

Environment and system requirementsThis section describes where to find interoperability and hostconfiguration information, and includes notes that are not found inother sources.

This section includes the following topics:

◆ “Interoperability information” on page 11

◆ “Kernel support” on page 13

◆ “Oracle Enterprise Linux and Asianux support” on page 18

◆ “HBA and driver support” on page 19

◆ “Storage system configuration” on page 19

◆ “Connectivity requirements” on page 19

◆ “File system support” on page 20

◆ “LVM2 support” on page 20

◆ “VxVM support” on page 20

◆ “Cluster support” on page 20

Interoperability informationPowerPath interoperability information appears in the E-LabInteroperability Navigator and in the EMC Host Connectivity Guide forLinux, available on the Powerlink website.

E-Lab Interoperability NavigatorFor interoperability information, such as information about thehardware, software, and networked storage components that aretested and compatible with both EMC storage systems andthird-party storage systems, refer to the E-Lab Interoperability

235871When you enter a value for powermt set path_latency_threshold that is invalid, an errormessage appears, but the message does not include the range of acceptable values.

5.0 5.3

Table 1 Fixed problems in PowerPath Version 5.3 and service pack releasesfor Linux (2 of 2)

DescriptionFound inversion

Fixed inversion


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Navigator, available on the Powerlink website. It also includesinformation about supported host models, operating systemrevisions, host bus adapters, and connectivity devices.

Note: The information in E-Lab Interoperability Navigator takes precedenceover the information in this release notice in case of inconsistency.

To access the E-Lab Interoperability Navigator:

1. Go to the Powerlink website.

2. Select Support > Interoperability and Product LifecycleInformation > E-Lab Interoperability Navigator.

3. Click Launch E-Lab Interoperability Navigator.

4. For interoperability information on PowerPath with EMC arrays:

a. Click the Wizards tab.

b. From the menu at the top right of the page, select SoftwareSupport Wizard.

c. Select PowerPath from the Product list, and then select theproduct version.

d. Select the operating system and model.

e. In the Results section on the right side of the page, click theCombined Results link to view the interoperabilityinformation for the PowerPath software you selected.

For interoperability information on PowerPath with third-partyarrays:

a. Click the PDFs and Guides tab.

b. Scroll down to the Infrastructure Software heading, andselect the PowerPath PDF.

EMC Host Connectivity Guide (EMC storage arrays)The EMC Host Connectivity Guide for Linux describes the features andsetup procedures for host interfaces to Symmetrix and CLARiiONstorage systems. Host connectivity guides are updated quarterly andpublished on the Powerlink website.

Note: Information in the host connectivity guide takes precedence over theinformation in this release note.



Kernel support Table 2 on page 13 summarizes kernel support for the PowerPathVersion 5.3 and service pack releases.

Note: The E-Lab Interoperability Navigator contains the latest supportedkernels. Information in the E-Lab Navigator supersedes information in theserelease notes.

PowerPath Version 5.3 and service pack releases supports the Linuxkernels shown in Table 3 on page 13.

Note: PowerPath Version 5.3 SP2 supports only SLES11.

Table 2 PowerPath kernel support

PowerPathRelease

Supported Linux distributions

RHEL

4.2

to4.

7

RHEL

4.8

RHEL

5to

5.3

RHEL

5.4

SLES

9SP

4

SLES

10SP

2

SLES

10SP

3

SLES

11

5.3 ✔ — ✔ — ✔ ✔ — —

5.3 SP1 ✔ ✔ ✔ ✔ ✔ ✔ — —

5.3 SP1 P01 — — — — — — ✔ —

5.3 SP2 — — — — — — — ✔

Table 3 PowerPath Version 5.3 and service pack releasessupported kernels (1 of 6)

Distributiona Architecture Minimum kernel and kernel type

RHEL 4.2 x86 uniprocessor default-2.6.9-22.EL

x86 multiprocessor smp-2.6.9-22.EL

hugemem-2.6.9-22.EL

AMD64/EM64T default-2.6.9-22.EL

smp-2.6.9-22.EL

IA64 default-2.6.9-22.EL


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hugemem-2.6.9-34.EL

AMD64/EM64T smp-2.6.9-34.EL

largesmp-2.6.9-34.EL




hugemem-2.6.9-42.EL






hugemem-2.6.9-55.EL






hugemem-2.6.9-67.EL










hugemem-2.6.9-78.EL





x86multiprocessor smp-2.6.9-89.EL

hugemem-2.6.9-89.EL




RHEL 5 x86 default-2.6.18-8.el5

PAE-2.6.18-8.el5

xen-2.6.18-8.el5

AMD64/EM64T default-2.6.18-8.el5

xen-2.6.18-8.el5

IA64 default-2.6.18-8.el5

xen-2.6.18-8.el5




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RHEL 5.1 x86 default-2.6.18-53.el5

PAE-2.6.18-53.el5

xen-2.6.18-53.el5


xen-2.6.18-53.el5


xen-2.6.18-53.el5


PAE-2.6.18-92.el5

xen-2.6.18-92.el5


xen-2.6.18-92.el5


xen-2.6.18-92.el5

PPC64 default-2.6.18-92.el5


PAE-2.6.18-128.el5

xen-2.6.18-128.el5


xen-2.6.18-128.el5


xen-2.6.18-128.el5

PPC64 2.6.18-128.el5.ppc64






PAE-2.6.18-164.el5

xen-2.6.18-164.el5

AMD64/EM64T kernel-2.6.18-164.el5

kernel-xen-2.6.18-164.el5

x8664 default-2.6.18-164.el5

xen-2.6.18-164.el5


xen-2.6.18-164.el5

PPC64 2.6.18-164.el5.ppc64

SLES 9 SP4 x86 default-2.6.5-7.308

smp-2.6.5-7.308

bigsmp-2.6.5-7.308

AMD64/EM64T smp-2.6.5-7.308

IA64 default-2.6.5-7.308

SLES 10 SP2 x86 default-2.6.16.60-0.21

smp-2.6.16.60-0.21

bigsmp-2.6.16.60-0.21

xen-2.6.16.60-0.21

xenpae-2.6.16.60-0.21

AMD64/EM64T smp-2.6.16.60-0.21

xen-2.6.16.60-0.21

IA64 default-2.6.16.60-0.21

PPC64 ppc64-2.6.16.60-0.21




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Oracle Enterprise Linux and Asianux supportTable 4 on page 19 summarizes Oracle Enterprise Linux (OEL) andAsianux support for the PowerPath Version 5.3 and service packreleases.

SLES 10 SP3 x86 2.6.16.60-0.54.5-default

2.6.16.60-0.54.5-smp

2.6.16.60-0.54.5-bigsmp

2.6.16.60-0.54.5-xen

2.6.16.60-0.54.5-xenpae

AMD64/EM64T 2.6.16.60-0.54.5-smp

2.6.16.60-0.54.5-xen

IA64 2.6.16.60-0.54.5-default

PPC64 2.6.16.60-0.54.5-ppc64

SLES 11 x86 default-2.6.27.19-5.1

pae-2.6.27.19-5.1

xen-2.6.27.19-5.1

xenpae-2.6.27.19-5.1

x86_64 default-2.6.27.19-5.1

xen-2.6.27.19-5.1

IA64 default-2.6.27.19-5.1

PPC64 ppc64-2.6.27.19-5.1

a. Refer to the E-Lab Interoperability Navigator for the supported kernelrevisions within this update/service pack.





Note: The E-Lab Interoperability Navigator contains the latest supportedkernels. Information in the E-Lab Navigator supersedes information in theserelease notes.

HBA and driver supportFor more information on the qualification of PowerPath Version 5.3for Linux for use on all arrays with the HBA drivers, refer to theE-Lab Interoperability Navigator.

Storage system configurationRefer to the EMC host connectivity guide for your operating systemfor information on setting up connections for Symmetrix andCLARiiON systems. For information on setting up connections forthird-party storage systems, refer to your vendor’s documentation.

For interoperability information for EMC and third-party storagearrays, refer to the E-Lab Interoperability Navigator, available onPowerlink.

Connectivity requirementsRefer to the E-Lab Interoperability Navigator for information onFibre Channel and iSCSI components and configurations supportedby PowerPath.

Table 4 PowerPath OEL and Asianux support

PowerPathRelease

Supported distributions

OEL 4.8OEL5.1, 5.2 Asianux 2.0 Asianux 3.0

Asianux3.0 SP1

Asianux3.0 SP2

5.3 — ✔ ✔ ✔ ✔ —

5.3 SP1 ✔ ✔ ✔ ✔ ✔ ✔

5.3 SP1 P01 — — — — — —

5.3 SP2 — — — — — —


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Note: Install HBAs, supported firmware versions, and other networkcomponents using the manufacturer’s directions and the settings specified inthe E-Lab Interoperability Navigator. Using improper settings can causeerratic failover behavior or extended response time for system I/O.

File system support Table 5 on page 20 summarizes the file systems supported byPowerPath.

LVM2 support PowerPath supports LVM2 on all its supported platforms.

LVM2 interoperability is supported for the native boot device as wellas PowerPath pseudo devices.

VxVM support For more information on VxVM support, see the E-LabInteroperability Navigator on Powerlink.

Note:—VxVM is not supported on Asianux.—Use native names to ensure PowerPath-managed devices on third-party

storage systems work properly with VxVM.—VxVM is supported on PowerPath 5.3 SP2 with Symmetrix and CLARiiON

storage arrays only.

Cluster support Refer to the E-Lab Interoperability Navigator for the currentinformation on cluster support.

Table 5 PowerPath File system support

PlatformFile System

ext2 ext3 ReiserFS

RHEL 4.2 to 4.8 ✔ ✔ —

RHEL 5 to 5.4 ✔ ✔ —

SLES 9 SP4, 10 SP2/SP3 ✔ ✔ ✔

SLES 11 ✔ ✔ ✔

Asianux 2.0, 3.0, 3.0 SP1,3.0 SP2

✔ ✔ —


Known problems and limitations

Known problems and limitationsThis section describes known problems in PowerPath Version 5.3 andservice packs for Linux.

This section includes the following topics:

◆ “Known PowerPath problems” on page 21

◆ “Known interoperability problems” on page 29

◆ “Limitations” on page 32

Known PowerPath problemsThe following problems have been reported for PowerPathVersion 5.3 and service pack releases for Linux.

Table 6 Known problems in Version 5.3 and service pack releasesfor Linux (1 of 8)

Description WorkaroundFound inversion

324315SLES10 SP2 or SP3 host attached to iSCSI CLARiiON ALUA LUNsmay hang during boot up. The issue requires multiple host reboots tobe observed.

It is recommended to change the failovermode to PNR (mode=1) if this problem isconsistently seen.

5.3 SP1

323229On SLES10 SP3, if the root filesystem is created on a logical volume,CLARiiON LU trespass performed using array management softwarecauses IO errors on PowerPath devices due to interference frommodule of DM-Multipath.

Refer to primus case emc229781 forworkaround.

5.3 SP1P01

322760PowerPath pseudo name may change if the following operations areperformed in sequence:• Manual Tresspass of the CLARiiON LUN using the Navisphere

GUI.• Causing an all paths down of the LUN owning SP.• Issuing a Host Reboot while the paths are down.

5.3.0

315870With CLARiiON devices running PPC64, managing back the entireCLARiiON class will result in a warning message with the CLARiiONclass moving into a manage_incomplete state.

Restarting the /etc/init.d/PowerPath servicewill get back the CLARiiON devices andchange the state to managed.

5.3 SP1


22


314671Switching between kernels on the same architecture in aboot-from-SAN environment may display a "Starting PowerPath:Stopping PowerPath:" message during host reboot. In productionservers, configuring multi-boot host and switching between multipleoperating systems is a rare scenario.

When switching between kernels (for example,2.6.27.19-5-default to 2.6.27.19-5-pae),perform the following:1. Host is booted in default operating system

(2.6.27.19-5-default) with initrd createdwith PowerPath modules(initrd-pp-2.6.27.19-5-default).

2. Reboot the host in PAE operating system(2.6.27.19-5-pae) with initrd provide by theoperating system (initrd-2.6.27.19-5-pae).

3. Reboot the host in PAE operating system(2.6.27.19-5-pae) with initrd created withPowerPath modules(initrd-pp-2.6.27.19-5-pae).

5.3 SP2

313099PowerPath does not start upon reboot when /usr is on a separatemount point. If PowerPath is installed and not manually started beforerebooting, the PowerPath modules are not loaded. This issue is notseen on SLES11 hosts.

Start PowerPath immediately after PowerPathhas been installed or manually startPowerPath once the host has come up.

5.3 SP1

308967Running powermt watch or powermt display every=seconds whena path has failed and then restored may continue to displayUNKNOWN.

Stopping the powermt watch or powermtdisplay command and then starting a newsession will show the updated information.

5.3 SP2

294743If the iSCSI device or the logical volume on an iSCSI device ismounted on SLES 10 SP2 hosts, rebooting the host hangs atUnmounting File System.

Unmount the logical devices or the logicalvolumes before the system is rebooted orshutdown.

5.3

293597During boot up on RHEL 5 hosts, fsck service could not find theemcpower device to perform file system check. Host doesn’t boot.

See “The _netdev option in /etc/fstab” onpage 42".

5.3

291832Active Logical Volume on a failed device prevents PowerPathuninstall.

Perform the following:1. Connect at least one path to the device(s)

hosting the active logical volume.2. Make the logical volume inactive by typing:lvchange -a n<logical_volume>

Alternatively, restart the host.

5.1 SP3





288172RHEL 4.5 iSCSI host panics and hangs when any pseudo device is inuse (that is, mounted and FS I/O or raw I/O on it). The only option isto power-cycle the host.

See “The _netdev option in /etc/fstab” onpage 42".Stop all I/O to the device before rebooting thehost.

5.1 SP2

285141With raw I/Os running on the pseudo device, the PowerPath 5.1 SP2uninstallation hangs the SLES 10 SP2 host.

Stop all I/O to PowerPath devices beforeuninstalling PowerPath.

5.1 SP2

285139When running scandisks for Oracle ASM volumes on PowerPath5.1.x, the host hangs. This issue is seen with a larger number ofvolumes.

None. 5.1

284679When both iSCSI ports are disabled in an iSCSI RHEL 5.2 setup, thehost continuously throws call trace messages on the console.

None. 5.1 SP2

284450When starting PowerPath 5.1 SP2 with RHEL 5.2, a segmentationfault occurs with emcpmgr map.Related OPTs: 284302, 284451, 285294, 292949.

Perform the following:1. Delete the old .FCS files from the /etc

directory,2. Start PowerPath by typing:/etc/init.d/PowerPath start

If that does not fix the issue, follow theadditional procedure:1. Uninstall PowerPath2. Rename the /etc/emc/ to /etc/emc_bkup/.

Re-install PowerPath.The licenses can be retrieved from thebacked-up/etc/emc_bkup/archive/emcp_regisration.saved file.

5.1 SP2

283678When disabling and re-enabling HBA-1 on systems runningPowerPath 5.1 SP2 with SLES 10 SP2, powermt display outputshows the HBA as UNKNOWN.

Stop powermt display, and then runpowermt display again.

5.1 SP2

281891In systems running on RHEL 4, the existing parted versionparted-1.6.19.EL does not work correctly on pseudo devices.Related OPTs: 218291, 279285.

Use the fdisk utility instead of parted to createpartitions using pseudo devices. Upgrade toparted version parted-1.6.21 series or later.

5.1




24


281284On a Linux host, a file system cannot be mounted after a LUNtrespass and then a host reboot. PowerPath does not update theoperating system partition table for the LUN because the partitiontable doesn’t contain entries for passive paths.

Run blockdev -rereadpt on the device afterthe host reboot.

5.3

277502Upgrading from PowerPath 5.0 to 5.3 fails with a "device in use" errormessage while the hwscan process is running.

Before upgrading to PowerPath Version 5.3,wait until the hwscan process is complete.

5.3

277060On SLES 10 SP1 and RHEL5.1, the system is unable to create LVMvolume from a PowerPath pseudo device using a resized LUN.

None. 5.1 SP1

276250iostat does not show output for native devices associated to anypower device when I/Os are started using the power device, andvice-versa.

None. 5.1 SP1

275920On SLES 10 SP1 and RHEL 5.1 with either PowerPath 5.1 orPowerPath 5.1 SP1 installed, PowerPath does not recognize thewrite_enable status of a device that was added as a write_disabledevice. This issue is not a regression of PowerPath 5.1 SP1 andaffects only newer kernels.

Perform the following:1. Run /etc.init.d/PowerPath stop to stop

PowerPath.2. Run /etc/init.d/PowerPath start to start

PowerPath.

5.1 SP1

269464, 268353LCC Card & Disk Pull related issues: Paths toggle between dead andalive states before being marked dead.

If a rare situation does occur where the LUNtoggles between dead and alive statecontinuously, a powermt restore commandcan be run to mark the device as dead.

5.1

266872With the open-iSCSI Initiator on SLES10 and RHEL5 CLARiiONhosts in a typical configuration, the powermt display shows fourinitiators instead of one. This results in getting only one Active pathand the rest as UnLic paths, that is a violation of the Basic Failoverpolicy. It may also result in the LUN getting trespassed due toPowerPath possibly picking up a path from the non-owning storageprocessor and activating it; this will occur due to PowerPath randomlypicking up a path and activating it.

None. 5.1

265610Certain iSCSI CLARiiON (ALUA and PNR) devices are trespassedduring the system startup procedure.

If a trespass is observed, add a sleep of 180seconds in the PowerIscsi script beforerunning powermt config.

5.1





264469Unnecessary path failures were found while removing the LUN (withhostid 0) from the storage group. The LUN had file system I/Orunning. This issue was found on the SLES10 SP1 (ia64) platformzoned to the CLARiiON array with FLARE Operating Environmentversion 26.

None. 5.1

263813On booting your system, iSCSI targets are not automaticallydisplayed on the SLES 9, SLES10 and SLES10SP1 hosts.

With PowerPath 5.1 or later, to automaticallydisplay iSCSI targets on the SLES 9, SLES10and SLES10SP1 hosts, add the sleep 30command at the beginning of the open-iscsiscript.

5.0.1

263754The powermt display command shows a large number ofqueued-I/Os while running IOzone to the boot-from-SAN device.

None. 5.0.1

260309Diskdump fails if the PowerPath device is specified, but it succeeds ifthe SD device is specified.

Diskdump to the native SD devices withPowerPath installed on the host is successful,provided the native device path correspondingto the device selected as the dump device isactive when the system crashes or diskdumpis initiated.Diskdump can use one of multiple configureddevices to store a crash dump. Consequently,all of the native paths to a dump device can bespecified. With such a configuration, diskdumpattempts dumping via each successive pathuntil it finds an active path to dump.For example, if there are four paths to a deviceassigned to the host, all of them can bespecified as a colon separated list of thecorresponding native devices in the diskdumpconfiguration file -/etc/sysconfig/diskdump.DEVICE=/dev/sdk1:/dev/sdy1:/dev/sdao1:/dev/sdbc1.

5.0.1

259928This problem occurs on both RHEL 5 and SLES 10 SP1 hosts. Aftera path failure, PowerPath allows the last active path to be removed,leading to file system corruption.

None. 5.0.1




26


259109If both LCC cards (LCC A and LCC B) fail, the LUN continuouslytrespasses from SPA to SPB and back. PowerPath does not detectthe path failure.

None. 5.0.1

258859A double fault on RAID-protected LUNs (caused when more than oneCLARiiON disk in a RAID group fails) causes the LUNs tocontinuously trespass from SPA to SPB and vice versa. PowerPathdoes not detect the path failures.

None. 5.0.1

258496During partition creation, the required number of partitions is notachievable. This results in, during the execution of the partedcommand, displaying error messages if udev is also running on ahost.

If the parted command is run by the user onthe shell prompt to create partitions, instead ofexecuting the parted command to createmultiple partitions all at once through a singlecommand, create the partitions at the partedcommand prompt "(parted)" using the mkpartcommand, one partition at a time.If the parted command is run by the user aspart of a script to automate partitioning, thenignore the error messages. Ensure to includea 30-second delay between parted commandsto enable the udev events to settle down.

5.0.1

257208The parted command returns an error message when you attempt tocreate or modify two or more partitions. Despite the message, thepartitions are created successfully.

None. The partitions are created successfully. 5.0

245703On hosts connected to a CLARiiON storage system through iSCSI,after installing and then starting PowerPath (/etc/init.d/PowerPathstart), a segmentation fault (SIGSEGV) may occur. The presence ofold .FCS files in the /etc directory causes the fault.

Delete the old .FCS files from the /etcdirectory and then restart PowerPath by typing/etc/init.d/PowerPath start.

5.0

238768On hosts that are running RHEL4 U2 and later, PowerPath SE (theunlicensed version of PowerPath) does not support back-end failoverfor storage systems that are attached through iSCSI.

None. 5.0





237428When you install PowerPath 5.0, messages similar to the followingmay get logged in the /var/log/messages file:Jul 4 11:31:00 libg181 kernel: emcp: module notsupported by Novell, setting U taint flag.Jul 4 11:31:00 libg181 kernel: emcpmpx: modulenot supported by Novell, setting U taint flag.

Ignore the messages. 5.0

237040Unmanaging Symmetrix devices with the powermt unmanageclass=symm command requires a host reboot before re-managingthem, even when no devices are being kept open by applications.

None. 5.0

231632On SLES 9 SP3, running the OracleASM start/scandisks/stopcommands may panic the host after 20–30 iterations of the loop.

None. 4.5.1

224613If you are running Emulex HBAnyware, and attempt to install oruninstall PowerPath, the installation (or uninstallation) hangs.This problem is also seen if you attempt to install or uninstall VeritasVolume Manager while HBAnyware is running. Similar problems mayoccur if you attempt to install Storage Foundation HA, StorageFoundation for Oracle RAC, and similar products, while you arerunning HBAnyware.

Stop the Emulex application kit before youinstall PowerPath or Veritas applications.1. Exit the HBAnyware application if it is

launched.2. Type

# /usr/sbin/hbanyware/stop_hbanywareto stop the HBAnyware daemons.

3. Install the PowerPath (Veritas, or anyaffected) package. (See Note)

4. Type# /usr/sbin/hbanyware/start_rmserver/usr/sbin/hbanyware/start_elxdiscoveryto restart the HBAnyware daemons.

5. Relaunch HBAnyware application ifrequired.

Note: If you restart the system after installingPowerPath (or Veritas), after the restart it isnot necessary to restart the HBAnywaredaemons. rmserver is restarted upon reboot,and elxdiscovery starts on the first invocationof HBAnyware.

4.5




28


223441Upon restarting PowerPath after installing PowerPath or after deviceconfiguration changes, the /etc/init.d/PowerPath start commandfails, though devices are configured. Alternatively, you may see amessage that PowerPath fails to start.

Type /etc/init.d/PowerPath start a secondtime. The command should completesuccessfully.

In the case of segmentation faults(SIGSEGV), delete the old .FCS files from the/etc directory and then restart PowerPath.

4.5

214659Symmir will not establish a BCV mirror using the PowerPath pseudoname of a Symmetrix metavolume.

Use the native volume name. 4.4





Known interoperability problemsTable 7 on page 29 summarizes the known interoperability problemsthat affect PowerPath.

Table 7 Known interoperability problems (1 of 3)


318268With the boot device encapsulated under VxVM control, running vxdiskscandisks after reboot stops the vxconfigd daemon in the presence ofPowerPath service. This is a Symantec issue with VxVM 5.0 MP3 RP2.

After a reboot, run vxconfigd -k to restartthe configuration daemon and then runvxdisk scandisks.

5.3

313031After over-provisioning the thin pool on a CLARiiON array with FLAREversion 04.28.000.5.706, the hosts connected to the CLARiiON receivesSCSI related errors and does not see all the thin LUNs after a hostreboot.

Tracking number: DIMS 217555

This is a CLARiiON issue that has beenfixed in FLARE version 04.29.

5.3 SP2

312289Multiple disk failures with I/O errors, results in call trace messages onthe console.

None. 5.3 SP2

309245Logical Volume Manager (LVM) volumes on PowerPath iSCSI pseudodevices do not get automatically mounted after reboot.

Novell tracking number: Bugzilla #485473

To ensure all of the LVMs are mountedproperly after reboot, use the LVM volumes/dev/mapper paths and the nofail option inthe /etc/fstab file for the iSCSI devices.Refer to “Mounting pseudo devicesautomatically after reboot (SLES 11)” onpage 42 for more information.

5.3 SP2

308073On SLES 11 hosts, PowerPath is not starting the volume groups basedon /etc/sysconfig/lvm config file parameter during host boot.


Update the LVM2 package to the latestusing YaST online update.

5.3 SP2

307676Admsnap not able to activate and deactivate session on snapshot LUN.


This issue has been fixed with admsnapversion admsnap-2.29.0.0.2-1.

5.3 SP2


30


307670Naviagent fails to start on SLES 11 IA64 server.


This issue has been fixed with Naviagentversion 6.29.0.5.38..

5.3 SP2

307520On SLES 11 hosts, filesystem and LVM created on fibre channelpseudo devices will not get automatically mounted and the fsck checkcannot find the pseudo devices after host reboot.


Refer to “Mounting pseudo devicesautomatically after reboot (SLES 11)” onpage 42 for more information.

5.3 SP2

295436After a host reboot on SLES 9 SP4 hosts, volumes managed by LogicalVolume Manager (LVM) remain open though they are not in use.Attempts to remove or deactivate the LVM volumes fail. This is not aPowerPath issue.

To remove the logical volume after a hostreboot:1. Run dmsetup remove <device_name>.2. Run lvremove <device_name>.

5.3

287890Due to issues with Asianux Server 3, write/read to PowerPath causesthe Asianux Server 3 iSCSI host to reboot.

To resolve, install Asianux Server 3 SP1.The issue is fixed in the Asianux Server 3SP1 kernel.

5.1 SP2withAsianuxServer 3

286783On the SLES operating system only, the number of trap messagesreceived are more than the number of dead paths on the host.


None. 5.3

286379On a Linux host with Veritas Storage Foundation (VSF) installed, VxVMprevents the upgrade and uninstallation of PowerPath Version 5.3. Thisis a Symantec issue.

Perform the following:1. Remove or offline the devices from

VxVM control:• For Veritas 4.1 MP4

Type vxdisk offline <emcpowerX>• For Veritas 5.0 MP3

Type vxdisk rm <emcpowerX>2. Upgrade or uninstall PowerPath.

5.3





280150On RHEL 4.x x86_64 and i386 hosts with QLogic cards, the host panicsand does not display a module in use error message when the HBAdrivers are unloaded while PowerPath is running.

This issue was resolved by QLogic inRHEL 5 and SLES 10.To workaround, unload the HBA drivers onRHEL 4 hosts:1. Run /etc/init.d/PowerPath stop to stop

PowerPath.2. Unload or load the HBA drivers.3. Run /etc/init.d/PowerPath start to start

PowerPath.

5.3 withRHEL 4.xx86_64and i386

266101RedHat reports that with PowerPath installed, the iostat utility reportsincorrect utilization numbers (greater than 100%) against an internalMegaRAID volume.This is an operating system issue.This issue is also documented in EMC Knowledgebase Solutionemc191477.

None. 5.1

264352If modprobe -r qla2300 is run, the module gets unloaded properlyinstead of the 'module in use' error message being displayed. Thisscenario occurs with PowerPath being active on a SLES9_i386_SP3host. Thereafter, powermt display dev=all displays all the devicesalbeit with one path each.Related OPT: 280150

This issue was resolved by QLogic inRHEL 5 and SLES 10.

5.1

256449For Symmetrix devices, powermt display shows numerous devicepaths for each pseudo device. This is a QLogic driver issue.

Perform the following:1. Edit the /etc/modprobe.conf file by

adding the line:options scsi_moddev_flags=EMC:SYMMETRIX:0x20240

2. Rebuild the initrd image.

5.0.1

226467Starting PowerPath on a SLES 9 host with a qla4xxx iSCSI driver maygenerate the following message:qla4xxx: invalid ioctl magic number received.

This is a QLogic driver issue.

Ignore the message. 4.5




32


Limitations This section includes the limitations in PowerPath Version 5.3 andservice pack releases.

PowerPath 5.3 SP1 P01 PowerPath Version 5.3 SP1 P01 for Linux has the followinglimitations:

◆ PowerPath Version 5.3 SP1 P01 only supports SLES10 SP3 anddoes not support PowerPath Encryption with RSA.

◆ IBM Power (IBM PPC) is not supported on PowerPath MigrationEnabler.

PowerPath 5.3 SP2 PowerPath Version 5.3 SP2 for Linux has the following limitations:

◆ PowerPath Version 5.3 SP2 only supports SLES11 and does notsupport PowerPath Migration Enabler or PowerPath Encryptionwith RSA.

◆ PowerPath Version 5.3 SP2 does not support native devices onfibre channel hosts running SLES 11 and later kernels that havethe dynamic /dev directory. “SLES 11 path failure behavior” onpage 35 provides additional information.

◆ IBM Power (IBM PPC) is not supported on PowerPath MigrationEnabler or PowerPath Encryption with RSA.

◆ Access to the same LUN from the same host over both FibreChannel and iSCSI is not supported.

PowerPath 5.3 and5.3 SP1

PowerPath Version 5.3 and 5.3 SP1 for Linux has the followinglimitations:

◆ iSCSI on PowerPC is not supported on PowerPath Version 5.3and 5.3 SP1.

◆ IBM Power (IBM PPC) is not supported on PowerPath MigrationEnabler or PowerPath Encryption with RSA.

◆ Veritas File System (VxFS) file systems are not supported onPowerPath pseudo devices without Veritas Volume Manager(VxVM) volumes.

◆ Access to the same LUN from the same host over both FibreChannel and iSCSI is not supported.

◆ VCS (Veritas Cluster Server) 5.0 MP3 in I/O fencing mode is notsupported on SLES 10 SP2 x86_64 hosts. OPT 296100 andSymantec Etrack 1518281 provide additional information.


Technical notes

◆ VCS 4.1 MP4 RP3 in I/O fencing mode is not supported onSLES 9 SP4 hosts. OPT 296434 provides additional information.

◆ Due to the OS recovery mechanism with respect to timeouts inI/O, sometimes LUN trespass and I/O resumption takes aroundfive minutes to complete in a SP hang scenario.

Technical notesThe Technical notes section includes the following topics:

◆ “Placing Celerra iSCSI devices under PowerPath control” onpage 34

◆ “SLES 11 path failure behavior” on page 35

◆ “Changing the device mapper devices dependency to pseudodevices (SLES 11)” on page 36

◆ “Setting periodic_autorestore to off still restores dead paths(SLES 11)” on page 36

◆ “PP_DISPLAY_TIME_STAMP environment variables” on page 37

◆ “emcpadm enhancements” on page 37

◆ “Management Daemon using SNMP” on page 37

◆ “IBM PowerPC support” on page 38

◆ “Supporting more than 256 storage devices” on page 38

◆ “Symmetrix Enginuity Operating Environment” on page 40

◆ “CLARiiON FLARE Operating Environment” on page 40

◆ “iSCSI devices” on page 40

◆ “Mode not reflecting properly across a reboot” on page 41

◆ “The _netdev option in /etc/fstab” on page 42

◆ “Mounting pseudo devices automatically after reboot (SLES 11)”on page 42

◆ “Expanding the file system on a pseudo-device” on page 42

◆ “Inconsistent VxVM pseudo-device mappings” on page 43

◆ “PowerPath licenses in a CLARiiON AX and CX configuration”on page 44


34

Technical notes

Placing Celerra iSCSI devices under PowerPath controlPowerPath treats Celerra® iSCSI devices as generic devices. Enablegeneric Loadable Array Module (LAM) support so that PowerPathcan recognize and manage Celerra iSCSI devices.

Managing Celerra iSCSI targetsTo place Celerra iSCSI devices under PowerPath control:

1. Add the following line to the /etc/emc/mpaa.lams file:

managed:generic:EMC:Celerra

2. Run the powermt init command.

3. Run the powermt config command.

4. Run the /etc/init.d/PowerPath stop;/etc/init.d/PowerPath start command sequence to restartPowerPath or reboot the host.

Unmanaging Celerra iSCSI targetsTo remove Celerra iSCSI devices from PowerPath control:

1. Remove the following line from the /etc/emc/mpaa.lams file:

managed:generic:EMC:Celerra

2. Run the powermt init command.

3. Run the powermt config command.

4. Run the /etc/init.d/PowerPath stop;/etc/init.d/PowerPath start command sequence to restartPowerPath or reboot the host.

PowerPath and the CLARiiON admsnap utilityTake note of the following if you use the CLARiiON admsnap utilitywith PowerPath devices.

◆ For all versions of the admsnap utility, set thePP_SHOW_CLAR_OWNING_SP environment variable to false tosuppress the display of default and current SP data:

PP_SHOW_CLAR_OWNING_SP=false

◆ For admsnap utility version 2.4.0.0.3 or less:


Technical notes

• Set the PP_DEFAULT_STORAGE_SYS environment variable toCLARiiON to restrict the class of devices displayed by thepowermt utility to CLARiiON devices:

PP_DEFAULT_STORAGE_SYS=CLARiiON

• Use a native PowerPath name (for example, /dev/sde) to startor activate an admsnap session when a file system is mountedon a PowerPath device. You cannot use a PowerPath pseudodevice name (for example, /dev/emcpowere) to start oractivate a session when a file system is mounted on aPowerPath device.

SLES 11 path failure behaviorPowerPath does not support native devices on SLES 11 and later dueto changes in operating system behavior. With SLES 11, the kernelobject and native device nodes are removed from the kernelfollowing a path failure. Due to the path failure, PowerPath displaysUNKNOWN in powermt display for the removed devices, as shownin the following output.

IMPORTANT!Use PowerPath pseudo devices for application I/Os such as filesystems and LVMs.

Pseudo name=emcpowerbSymmetrix ID=000190300895Logical device ID=01D5state=alive; policy=SymmOpt; priority=0; queued-IOs=0====================================================================----------- Host ----------- - Stor - - I/O Path - -- Stats --### HW Path I/O Paths Interf. Mode State Q-IOs Errors====================================================================

7 qla2xxx sdan FA 1cA active alive 0 07 qla2xxx sdaw FA 2cA active alive 0 06 UNKNOWN unknown FA 1cA active dead 0 06 UNKNOWN unknown FA 2cA active dead 0 0

After the path is restored, the latest device and HBA name appear inpowermt display output, but the names may be different dependingon the configuration or the order in which paths were restored.

Native devices are not supported in SLES 11 and later kernels exceptin the following situations:


36

Technical notes

Note: Native devices in PowerPath commands will continue to be supportedon releases earlier than SLES 11.

◆ Managing a LUN that was previously unmanaged with thepowermt manage command.

◆ Disabling or enabling an array port with the powermt setport_disable command.

Changing the device mapper devices dependency to pseudo devices (SLES 11)

IMPORTANT!On SLES 11 hosts, when the device mapper devices are started witha dependency on native devices, panics or crashes could occur onsubsequent path failures.

The device mapper devices may start with a dependency on nativedevices in the following scenarios:

Note: Run dmsetup deps to check the dependency of the device mapperdevices before running the pp_reset_dm_deps.sh script.

◆ On dynamic LUN addition, if volume groups (VG) are present onthe newly added LUNs, the VG may be activated with adependency on native devices.

◆ If a host is booted up with all paths down and then the paths arerestored, the VGs on the LUNs may become activated with adependency on native devices.

For PowerPath to work properly, run the/etc/opt/emcpower/pp_reset_dm_deps.sh script to reset thedependency to pseudo devices.

Setting periodic_autorestore to off still restores dead paths (SLES 11)On SLES 11 hosts, when the powermt set periodic_autorestorecommand is set to off, PowerPath will continue to test and restoredead paths. This is expected behavior on SLES 11 kernels.


Technical notes

PP_DISPLAY_TIME_STAMP environment variablesPowerPath Versions 5.3 SP2, 5.3 SP1 and later supports thePP_DISPLAY_TIME_STAMP environment variable which adds atime stamp to the powermt display command.

The format of the time display is defined by setting one of thefollowing values:

◆ TIME_VERBOSE—displays complete details such as day, month,and year, time in hours, minutes, and seconds that incrementsuntil you exit the powermt display command.

◆ TIME_SECONDS—starts a counter from zero that incrementsuntil you exit the powermt display command.

If the environment variable is not defined or if it is defined but notassigned a proper value the time stamp is not displayed.

The EMC PowerPath Family CLI and System Messages Reference Guideincludes additional information.

emcpadm enhancementsThe PowerPath command line utility, emcpadm, has been enhancedto export and import pseudo device name and logical unit data inXML format. The XML data is compatible with that viewed throughtools such as PowerPath powermt and Symmetrix syminq.

The emcpadm utility supports importing and exporting ofSymmetrix and CLARiiON array device data as well as that ofthird-party arrays. The importing and exporting of mapping data innon-XML format is limited to the arrays supported by PowerPath.

The EMC PowerPath Family CLI and System Messages Reference Guideincludes additional information on the enhanced emcpadmcommand line utility for importing and exporting in XML format.

Management Daemon using SNMPThe PowerPath Management Daemon provides an event and alertingmechanism for multipathing events listed in the emcp_mond.conffile. These SNMP traps are viewable through an SNMP manager anddisplay alerts based on filtering criteria, such as a path going dead.


38

Technical notes

The management daemon requires the net-snmp package to beinstalled and configured according to the net-snmp documentation.The management daemon sends SNMPv2c traps.

PowerPath management daemon on SLES 11 PPC64 hostsThe PowerPath management daemon requires the 32-bit version ofthe SNMP libraries, but if you are running SLES 11 PPC64architecture, SLES 11 does not install the 32-bit SNMP libraries. Touse the PowerPath management daemon on SLES11 PPC64 hosts, useYaST to install the 32-bit version of the SNMP libraries(libsnmp15-32bit) or install the 32-bit version of the SNMP librariesrpm package, and then configure the management daemon.

The EMC PowerPath for Linux Installation and Administration Guide,available on Powerlink, includes more information on themanagement daemon using SNMP.

IBM PowerPC supportPowerPath Version 5.3 on RHEL 5.2, RHEL 5.3, SLES 10 SP2, andSLES 11 supports IBM Power (IBM PPC), a feature that allowsPowerPath with Linux to run on IBM PowerPC (PPC64) hardware.IBM PowerPC is not supported on PowerPath Migration Enabler andPowerPath Encryption with RSA.

Note: PowerPath Versions 5.3 and PowerPath 5.3 SP1 does not support iSCSIon PowerPC.

PowerPath Version 5.3 and service packs support the following IBMPowerPC hardware:

◆ IBM System p5 Series servers

◆ IBM System p6 Series servers

◆ IBM BladeCenter JS21 blade servers

Supporting more than 256 storage devicesComplete the following steps to support more than 256 storagedevices on a host.

Emulex HBAs If you using Emulex HBAs, set the lpfc_max_luns parameter to 1024,2048, or 4096.


Technical notes

QLogic HBAs If you using QLogic HBAs, change the system parameters under/sys/module/scsi_mod/max_luns and max_report_luns to therecommended value.

For more information, refer to the EMC Host Connectivity Guide forLinux or to the vendor website.

Making the parameter settings permanent across rebootTo make the parameter settings permanent across reboot on Emulexor QLogic HBAs:

1. Edit the /etc/modprobe.conf file and set the lpfc_max_lunsparameter to 1024, 2048, or 4096.

2. Recreate the initrd.

3. Point the initrd to the new initrd when booting.

For more information, refer to the EMC Host Connectivity Guide forLinux or to the vendor website.

Unmanaging more than 256 LUNs causes PowerPath loading failures.To resolve the PowerPath loading failure:

1. Type mv /etc/init.d/PowerPath /etc/init.d/PowerPath.orig

2. Restart the host.

3. Remove /etc/emc/mpaa.excluded.

4. Edit /etc/modprobe.conf.pp to remove the excludedvolumesmodule parameter and its associated arguments.

5. Type mv /etc/init.d/PowerPath.orig /etc/init.d/PowerPath

6. Type /etc/init.d/PowerPath start.

7. Unmanage the devices (up to 256).

Configuring 256 devices in a boot-from-SAN environmentIn a boot-from-SAN environment, PowerPath configures only 256device paths, though more device paths are available to the system.

Perform the following:

1. Run /sbin/udevstart to repopulate the device directory.

2. Run powermt config.

3. Run chkconfig boot.udev on to configure udev to start upautomatically on subsequent reboots.


40

Technical notes

4. Run chkconfig boot.udev to confirm the change.

Symmetrix Enginuity Operating EnvironmentTake note of the following issues regarding the Symmetrix EnginuityOperating Environment.

Enginuity Operating Environment 5568 reservation and pre-emption commandsThe Reservation and pre-emption commands in EnginuityOperating Environment 5568 are not working according to the SCSI-3specification. This issue is seen both with PowerPath and withoutPowerPath on a host. This is not a PowerPath issue.

Enginuity Operating Environment 5773 and VxVMWith Symmetrix Enginuity Operating Environment 5773 and VxVM,Symmetrix patch 5773.130.90 or later is required. This patch fixes anissue where the vxfentsthdw utility fails while testing a SCSI-3persistent group reservation enabled LUN.

CLARiiON FLARE Operating EnvironmentTake note of the following issue regarding the CLARiiON FLAREOperating Environment.

FLARE Operating Environment 04.28 and over-provisioningAfter over-provisioning the thin pool on a CLARiiON array withFLARE version 04.28.000.5.706, the hosts connected to the CLARiiONreceives SCSI related errors and does not see all the thin LUNs after ahost reboot. This is a CLARiiON issue that has been fixed in FLAREversion 04.29.

iSCSI devices Take note of the following issues regarding native iSCSI devicesusing the software initiator in a PowerPath environment.

Configuring iSCSI to start on host bootEMC recommends configuring your iSCSI initiator service to startautomatically when the host boots. Run chkconfig to enable theiSCSI service.


Technical notes

Note: If you stop PowerPath and then the device configuration changes,when you restart PowerPath you may see a message that PowerPath failed tostart. You can ignore this message.

Stopping iSCSI on a PowerPath hostAlways stop PowerPath before stopping iSCSI on a host with iSCSIdevices under PowerPath control.

Note: Ensure that anything that has an iSCSI device open has closed the iSCSIdevice before shutting down iSCSI. This includes file systems, volumemanagers, and user applications.

To stop iSCSI on a PowerPath host:

1. Type /etc/init.d/PowerPath stop.

2. Type /etc/init.d/iscsi stop.

Adding or removing iSCSI devices"Dynamic LUN addition and removal" in the EMC PowerPath forLinux Installation and Administration Guide provides more informationon adding or removing iSCSI devices.

Running the powermt disable hba command may result in I/O failureOn SLES9 SP4, the iSCSI software initiator represents multiple iSCSIsessions as a single hardware path. Consequently, all iSCSI sessionswill be disabled and I/O errors result if powermt disable hba is run.

When working on a system with one iSCSI HBA, do not issuepowermt disable hba.

Running the powermt load command may give false warning messagesWith iSCSI Celerra devices, running powermt load gives a "Erroroccurred loading saved driver state from file /etc/powermt.custom"warning message although the configuration is restored. Because theconfiguration is restored, ignore the warning message.

Mode not reflecting properly across a rebootWhen a PowerPath load balancing and failover mode is changed, themode may not reflect properly after the reboot. This is caused by thenative device name sometimes changing during the reboot, creatingan incorrect configuration and is Linux operating system behavior.


42

Technical notes

The _netdev option in /etc/fstabFor RHEL 5, 5.1, 5.2, and 5.3, PowerPath devices should be mountedwith the _netdev option instead of the defaults option in the/etc/fstab file. This will ensure that fsck is run later in the bootsequence.

Mounting pseudo devices automatically after reboot (SLES 11)PowerPath fibre channel and iSCSI pseudo devices are notautomatically mounted after reboot due to an issue with the SLES 11and later operating systems. On Fibre Channel and iSCSI pseudodevices, use the nofail option on SLES 11 and later until Bugzilla#485473 and #523864 are fixed by Novell.

To mount Fibre Channel and iSCSI pseudo devices automatically andensure that fsck is run later in the boot sequence:

Note: The following workarounds for Fibre Channel pseudo devices applyonly to non-boot-from-SAN environments. In a boot-from-SAN environment,use the default settings in the /etc/fstab file.

◆ On Fibre Channel and iSCSI pseudo devices for filesystemswithout LVM, use the nofail option in the /etc/fstab file.

/dev/emcpowern /emcpowern ext3 rw,nofail 0 4/dev/emcpowercb /emcpowercb ext2 rw,nofail 0 5/dev/emcpowero1 /emcpowero1 reiserfs rw,nofail 0 6

◆ On Fibre Channel and iSCSI pseudo devices for filesystems withLVM, use the /dev/mapper path and the nofail option in the/etc/fstab file.

/dev/mapper/VG5_emcpowerai-lv5 /array/VG5_emcpowerai reiserfsrw,nofail 0 7

/dev/mapper/VG7_emcpowers-lv7 /array/VG7_emcpowers ext2rw,nofail 0 8

/dev/mapper/VG9_emcpowerae-lv9 /array/VG9_emcpowerae ext3rw,nofail 0 9

Expanding the file system on a pseudo-devicePowerPath does not recognize an expanded file system on anemcpower device unless you reboot the host.


Technical notes

After expanding the file system, type blockdev --rereadpt/dev/<pseudoname> so PowerPath correctly recognizes the expandedsize.

This issue is also documented in EMC Knowledgebase Solutionemc158004.

Inconsistent VxVM pseudo-device mappingsVxVM 4.1 or VxVM 5.0 pseudo-device mappings (emcpowermappings) may become inconsistent with PowerPath pseudo-devicemappings. Circumstances that may cause inconsistencies include:

◆ VxVM 4.1 is uninstalled and reinstalled after a LUNconfiguration change. VxVM maps pseudo-devices based ondevice information saved before the uninstall, and thesemappings may differ from the current PowerPath mappings andconfiguration.

◆ A pseudo-device instance is renamed using emcpadm, whichcauses VxVM 4.1 to lose the pseudo-device mapping.

Procedure To fix inconsistent device mappings:

◆ For VxVM 4.1 MP4:

1. Type cp /etc/vx/disk.info /etc/vx/disk.info.old.

2. Type echo > /etc/vx/disk.info.

3. Type vxconfigd -k.

This issue is also documented in EMC Knowledgebase Solutionemc126617.

◆ For VxVM 5.0 MP3:

1. Type vxddladm -c assign names.

The -c option clears all user-specified names and replacesthem with autogenerated names.

2. Type vxdisk scandisks.


44

Documentation

PowerPath licenses in a CLARiiON AX and CX configurationWhen running PowerPath without a license on a host attached toboth CLARiiON AX and CX arrays, PowerPath does not display awarning about the missing license for the CX array. This behaviormay be unexpected as PowerPath does display a missing licensewarning when connected to CX arrays when no AX array is present.Without a license, only the AX array has full PowerPath functionality;the CX array will not have failover support.

In a configuration with both CLARiiON AX and CX arrays, ensure avalid license is present for the CX array by entering emcpreg -list.

DocumentationThis section provides a list of the documentation that supportsPowerPath for Linux.

PowerPath documentationTable 8 on page 44 lists the PowerPath Version 5.3 for Linuxdocumentation set.

Localized versions of the EMC PowerPath for Linux Installation andAdministration Guide are available in French, German, Italian,Japanese, Korean, Portuguese, simplified Chinese, and Spanishlanguages.

The following documents describe the PowerPath Migration Enablersoftware:

Table 8 PowerPath Version 5.3 for Linux Documentation Set

Part Number Name

300-006-627 EMC PowerPath Family Version 5.2 and 5.3 Product Guide

300-008-343 EMC PowerPath Family CLI and System Messages Reference Guide

300-008-344 EMC PowerPath for Linux Version 5.3 Installation and AdministrationGuide

300-008-345 EMC PowerPath for Linux Version 5.3 and Service Pack ReleasesRelease Notes


Documentation

◆ EMC PowerPath Migration Enabler User Guide

◆ EMC PowerPath Migration Enabler Release Notes

The following documents describe the PowerPath Encryption withRSA software:

◆ EMC PowerPath Encryption with RSA User Guide

◆ EMC PowerPath Encryption with RSA Release Notes

Electronic versions of all PowerPath manuals are available on thePowerlink website. These manuals are updated periodically, and theupdated manuals are posted on the Powerlink website.

Related DocumentationThe following are related documentation for Symmetrix andCLARiiON storage systems.

Symmetrix storagesystems

If your environment includes Symmetrix storage systems, refer to thefollowing:

EMC Host Connectivity Guide for Linux, which provides basicinformation about the features and setup procedures for hostinterfaces to Symmetrix systems.

CLARiiON storagesystems

If your environment includes CLARiiON storage systems, refer to thefollowing:

◆ EMC Host Connectivity Guide for Linux, which provides basicinformation about the features and setup procedures for hostinterfaces to CLARiiON systems.

◆ CLARiiON Storage-System Support website(www.EMC.com\CLARiiONsupport).

Note: CLARiiON customers receive PowerPath with the CLARiiON UtilityKits that ship with CLARiiON CX- and CX3-series storage systems. Thisversion of PowerPath, referred to as PowerPath SE, provides basic failoverfor single HBA host configurations without the use of a license key. TheImportant Information About PowerPath SE document, available on thePowerlink website, provides additional information on the CLARiiONconfigurations supported by PowerPath SE.

If your environment includes other vendors’ storage systems, refer tothe appropriate documentation from your vendor.


46

Software media, organization, and files

End of service dates and extended supportEMC has a standard software support duration policy whichspecifies that a major version will reach End of Service Life (EOSL) aminimum of 36 months following the General Availability (GA).EOSL is followed by an Extended Support period during whichcustomers may elect to pay an additional fee to extend their supportcoverage rather than migrate to a current software version.

Once a software product reaches EOSL, EMC Technical Support is nolonger available under base support/maintenance agreements.Customers interested in uninterrupted support must upgrade to acurrent release or contract for Extended Support (ES).

Powerlink contains a list of documents that provide end-of-serviceand extended support information for PowerPath and other EMCsoftware and hardware products. To access these documents onPowerlink, select Support > Interoperability and Product LifecycleInformation > Product Release, End of Life Dates, Support Policy.

Note: This policy is in effect for select releases and will be phased in as newversions are made available. In cases where a software release is not eligiblefor Extended Support, the previous policy, which specifies product supportand maintenance under Continuous Coverage Product Maintenance(CCPM), terms still apply.

Software media, organization, and filesThis section describes the contents of the PowerPath for Linuxsoftware packages.

PowerPath 5.3 SP1 P01 EMC PowerPath version 5.3 SP1 P01 for Linux is a full releaseavailable for download from the Powerlink website.

PowerPath 5.3 SP1 EMC PowerPath Version 5.3 SP1 for Linux is a full release availablefor download from the Powerlink website.

PowerPath 5.3 SP2 EMC PowerPath Version 5.3 SP2 for Linux is a full release availablefor download from the Powerlink website.

PowerPath 5.3 EMC PowerPath Version 5.3 for Linux is a full release available onCD and for download from the Powerlink and EMC.com websites.


Software media, organization, and files

Media Table 9 on page 47 summarizes the PowerPath Version 5.3 for Linuxpackage.

Organization The software CD has the following structure:

/2.6/pp5.3.x

EMCPower.LINUX.5.3.GA.b185.tar.gz/rhel

EMCpower.LINUX-5.3.0.00.00-185.rhel.i386.rpmEMCpower.LINUX-5.3.0.00.00-185.rhel.ia64.rpmEMCpower.LINUX-5.3.0.00.00-185.rhel.x86_64.rpmEMCpower.LINUX-5.3.0.00.00-185.rhel5.i386.rpmEMCpower.LINUX-5.3.0.00.00-185.rhel5.ia64.rpmEMCpower.LINUX-5.3.0.00.00-185.rhel5.ppc64.rpmEMCpower.LINUX-5.3.0.00.00-185.rhel5.x86_64.rpm

/slesEMCpower.LINUX-5.3.0.00.00-185.sles.i386.rpmEMCpower.LINUX-5.3.0.00.00-185.sles.ia64.rpmEMCpower.LINUX-5.3.0.00.00-185.sles.x86_64.rpm

EMCpower.LINUX-5.3.0.00.00-185.sles10sp2.i386.rpmEMCpower.LINUX-5.3.0.00.00-185.sles10sp2.ia64.rpmEMCpower.LINUX-5.3.0.00.00-185.sles10sp2.ppc64.rpm

EMCpower.LINUX-5.3.0.00.00-185.sles10sp2.x86_64.rpm

Releases Table 10 on page 47 summarizes the PowerPath Version 5.3 for Linuxreleases.

Table 9 PowerPath Version 5.3 for Linux package

Part Number Description

053-002-203 A01 EMC PowerPath, PowerPath Migration Enabler, and PowerPathEncryption with RSA version 5.3 for Linux software CD.

Table 10 PowerPath Version 5.3 for Linux releases

PowerPath release Package Build

PowerPath Version 5.3 EMCPower.LINUX.5.3.GA.b185.tar.gz b185

PowerPath Version 5.3 SP1 EMCPower.LINUX.5.3.SP1.b111.tar.gz b111

PowerPath Version 5.3 SP1 P1 EMCPower.LINUX.5.3.SP1.P01.b008.tar.gz b008

PowerPath Version 5.3 SP2 EMCPower.LINUX.5.3.2.b029.SLES11.tar.gz b029


48

Installation

InstallationThe EMC PowerPath for Linux Installation and Administration Guide,available on Powerlink, includes instructions on installingPowerPath.

Localized versions of the Linux installer are available in French,German, Italian, Japanese, Korean, Portuguese, simplified Chinese,and Spanish languages.

Installation Guide updates since localizationTable 11 on page 48 summarizes the major differences between theEnglish version and the localized Installation and Administrationdocuments. EMC does not update the localized version.

Table 11 Installation Guide updates since localization

Revision Update

A02 Added "Upgrading PowerPath in a SteelEye LifeKeeper cluster environment"procedure.

Updated the Dynamic LUN addition procedure.

A03 Updated to include RHEL 4.8 and SLES 11 kernels.

Added "Configuring PowerPath in a boot-from-SAN setup (SLES 11)".

Added "Removing PowerPath in a boot-from-SAN setup (SLES 11)".

Added "Upgrading the Linux kernel in a boot-from-SAN setup (SLES 11)"

Added an install 32-bit SNMP library when running SLES 11 note to thePowerPath management daemon section.

A05 Updated to include SLES 10 SP3 kernel.


Troubleshooting and getting help

Troubleshooting and getting helpEMC support, product, and licensing information can be obtained asfollows:

Product information — For documentation, release notes, softwareupdates, or for information about EMC products, licensing, andservice, go to the EMC Powerlink website (registration required) at:

http://Powerlink.EMC.com

Technical support — For technical support, go to EMC WebSupporton Powerlink. To open a case on EMC WebSupport, you must be aWebSupport customer. Information about your site configuration andthe circumstances under which the problem occurred is required.

Service packs and upgrades — You can download PowerPathservice pack software from Powerlink. Determine which servicepacks (if any) you want to install after PowerPath, and whether thoseservice packs have any additional installation prerequisites. To obtainservice packs on Powerlink, select Support > Software Downloadsand Licensing > Downloads P-R > PowerPath for Linux.

EMC E-Lab Issue Tracker — EMC E-Lab Issue Tracker is anapplication that allows you to search for known problems and defectsin EMC software. To access EMC E-Lab Issue Tracker, on Powerlinkselect Support > Interoperability and Product LifecycleInformation> E-Lab Issue Tracker Information > E-Lab IssueTracker.

You can use Issue Tracker to find:

◆ Descriptions of PowerPath bugs existing on anyPowerPath-supported host platform.

◆ Workarounds for existing bugs.

This database is updated regularly between scheduled releases andservice pack releases.


http://powerlink.emc.com

50

Troubleshooting and getting help

Reporting a problemIf you find a problem in PowerPath, run the emcgrab utility, whichcollects system and software configuration information. Submit thegenerated tar file, along with any other supporting material, to EMCCustomer Support. PowerPath Encryption with RSA requiresemcgrab version 3.9 or later.

You can download emcgrab from the Powerlink website. SelectSupport > Product and Diagnostic Tools > Grab Utilities. Refer tothe emcgrab ReadMe.txt file on Powerlink for prerequisiteinformation and instructions on using the utility.

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EMC believes the information in this publication is accurate as of its publication date. The information issubject to change without notice.

THE INFORMATION IN THIS PUBLICATION IS PROVIDED “AS IS.” EMC CORPORATION MAKES NOREPRESENTATIONS OR WARRANTIES OF ANY KIND WITH RESPECT TO THE INFORMATION INTHIS PUBLICATION, AND SPECIFICALLY DISCLAIMS IMPLIED WARRANTIES OFMERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Use, copying, and distribution of any EMC software described in this publication requires an applicablesoftware license.

For the most up-to-date regulatory document for your product line, go to the Technical Documentation andAdvisories section on EMC Powerlink.

For the most up-to-date listing of EMC product names, see EMC Corporation Trademarks on EMC.com.All other trademarks used herein are t property of their respective owners.


Documents

EMC PowerPath for Linux Version 5.3 Service Pack · PDF filePowerPath operates on Red Hat Enterprise Linux (RHEL), SuSE Linux Enterprise Server ... Support for Encryption in a Veritas