Cisco MDS NX-OS Configuration Limits, Release 8.x

Cisco MDS NX-OS Configuration Limits 2

Switch-Level Fibre Channel Configuration Limits for Cisco MDS 9000 Series Switches 2

Fabric-Level Fibre Channel Configuration Limits for Cisco MDS 9000 Series Switches 4

Configuration Limits for Port Line Rate Throughput on Cisco MDS 9700 40 Gbps 24-Port FCoE Modules 6

Fibre Channel Topology Combinations and Scaling 7

Fibre Channel Scale Limitations 8

Syslog and Warnings for Fibre Channel Network Scale 9

Switch-Level Configuration Limits for Fibre Channel over Ethernet 10

Fabric-Level Configuration Limits for Fibre Channel over IP 11

Fabric-Level Configuration Limits for Fibre Channel over Ethernet (FCoE) on MDS 9700 Series 11

Cisco MDS 9000 I/O Accelerator Configuration Limits 12

Fibre Channel Flow Configuration Limits 13

Revised: February 26, 2021

Cisco MDS NX-OS Configuration LimitsThis document discusses the configuration and scalability limits for various SAN switching parameters in CiscoMDSNX-OS Release8.x:

Change History

DescriptionDate

Cisco MDS 9718 switches support 8000 FLOGIs per switch.July 1, 2020

The following scale values were updated:May 1, 2020

• CiscoMDS 9710 switches support 8000 FLOGIs per switch.

• Cisco MDS 9396T switches support 4000 FLOGIs perswitch.

• Smart Zones support a maximum of 250 members per zone.

Switch-Level Fibre Channel Configuration Limits for Cisco MDS 9000Series SwitchesSystem messages are generated whenever the configuration limits are exceeded. For more information, see the Cisco MDS 9000Series and Nexus 7000 Series NX-OS System Messages Reference document.

The following table lists the switch-level configuration limits for Cisco MDS 9000 Series switches:

Table 1: Switch-Level Configuration Limits

MDS9396T

MDS9148T

MDS 9132TMDS 9396SMDS 9148SMDS 9250iMDS 9700Series

ParameterFeatureName

256Footnote.256Footnote.256Footnote.256Footnote.256Footnote.256Footnote.256Footnote.FLOGIs orFDISCs perport

Fabric Logins

None (referto chassislimits)

None (referto chassislimits)

None (referto chassislimits)

None (referto chassislimits)

None (referto chassislimits)

None (referto chassislimits)

10002

20003FLOGIs orFDISCs permodule

20006

40007200020001000100040040004

80005FLOGIs orFDISCs perswitch

888888105NPV switchesper NPIV coreswitch

N-PortVirtualization(NPV)

2

MDS9396T

MDS9148T

MDS 9132TMDS 9396SMDS 9148SMDS 9250iMDS 9700Series

ParameterFeatureName

96 ISLs,each with15 VSANs,for a totalnumber of1440 portVSANinstances

48 ISLs,each with29 VSANs,for a totalnumber of1392 portVSANinstances

32 ISLs, eachwith 29VSANs, for atotal numberof 928 portVSANinstances

96 ISLs, eachwith 15VSANs, for atotal numberof 1440 portVSANinstances

48 ISLs, eachwith 29VSANs, for atotal numberof 1392 portVSANinstances

40 ISLs,each with29 VSANs,for a totalnumber of1160 portVSANinstances

Up to 200ISLs, eachISL with 16VSANs, for atotal numberof 3200-portVSANinstances

ISL instancesper switch 8

Inter-SwitchLinks (ISLs)

964832964840256Fibre Channelport channels

Port channels(PC)9

16161616161616Members ineach FibreChannel portchannel

NoneNoneNoneNoneNone8128Ethernet portchannels

NoneNoneNoneNoneNone816Members ineach Ethernetport channel

16161616161616SimultaneousSSH sessionsper switch

SSH 10

20,00020,00020,000NoneNoneNone20,00011

40,00012Active InitiatorTarget LUNs(ITLs) orInitiator TargetNamespace ID(ITNs) persamplinginterval perswitch

SANAnalytics andSANTelemetryStreaming

20,00020,00020,000NoneNoneNoneDS-X9648-1536K9:20,000

Active ITLs orITNs persamplinginterval permodule

222NoneNoneNone2Telemetryreceivers perswitch

1 This is the recommended limit. FLOGIs or FDISCs are not rejected until 512 logins have been accepted on the port.

3

2 Supported in Cisco MDS 9706 and 9710 switches.3 Supported in Cisco MDS 9718 switches.4 Supported in Cisco MDS 9706 switches.

Supported in Cisco MDS 9710 switches in Cisco MDS NX-OS Release 8.4(1a) and earlier releases.5 Supported in Cisco MDS 9710 switches with Cisco MDS 9700 Series Supervisor-4 Module (DS-X97-SF4-K9) from CiscoMDS NX-OS Release 8.4(2) and later releases.

Supported in CiscoMDS 9718 switches with CiscoMDS 9700 Series Supervisor-1Module (DS-X97-SF1E-K9) or CiscoMDS9700 Series Supervisor-4 Module (DS-X97-SF4-K9) from Cisco MDS NX-OS Release 8.4(2a) and later releases.

6 Supported in Cisco MDS NX-OS Release 8.4(1a) and earlier releases.7 Supported from Cisco MDS NX-OS Release 8.4(2) and later releases.8 ISLs can be an individual FC link, VFC link, FC port channel, or VFC port channel. One port channel interface with up to 16member links is considered as one ISL instance.

9 A system message appears in the user’s session when the maximum supported limit of port channels and member ports isexceeded.

10 A system message appears on the user’s session when the maximum supported number of SSH sessions is exceeded.11 Supported in Cisco MDS NX-OS Release 8.3(1) and earlier releases.12 Supported from Cisco MDS NX-OS Release 8.3(2) and later releases.

When there are more than 40,000 ITLs or ITNs distributed across multiple modules in multilayer directors or 20,000 ITLs orITNs in fabric switches, a random set of ITL or ITN data is reported. The ITL or ITN data may change frequently and becomesunpredictable. Hence, we recommend that you limit the number of ITLs or ITNs in a switch to less than the maximum limit orquery only view types. For example, a single query configured can display up to the maximum active ITLs or ITNs. If thereare two queries configured, the queries together can display up to the maximum active ITLs or ITNs.

Fabric-Level Fibre Channel Configuration Limits for Cisco MDS 9000 SeriesSwitchesThe following table lists the configuration limits for Cisco MDS 9000 fabrics.

Table 2: Fabric-Level Configuration Limits

MDS Mixed Fabric

(mix of MDS 9700, 9500, 9300,9200, 9100)

MDS 9700-only Fabric

(without MDS 9500, 9300, 9200,and 9100)

ParameterFeature Name

321380VSANs per physical fabricVSANs

1000015

13000Footnote.

20000`14FCNS entries in fabricLogins and aliases

800020000Device alias entries in fabric

4

MDS Mixed Fabric

(mix of MDS 9700, 9500, 9300,9200, 9100)

MDS 9700-only Fabric

(without MDS 9500, 9300, 9200,and 9100)

ParameterFeature Name

8080Domains per physical fabricDomains and hops

77Switch hops from server to storage

10001000Active zone setsZones and Smart Zones

800018

10400Footnote.

16000 17Active zones

1600021

20800 Footnote.

32000 20Active zone members19

2 MB

3.8 MBFootnote.

3.8 MB 22Active zone database size

3232Active IVR zone setsInter-VSAN Routing(IVR)

2000Footnote.2000Footnote.Active IVR zones

40004000Active IVR zone members

1616Active IVR service groups

8080CFS peersFootnote.CFS

100100CFS static peers over IPFootnote.

13 In a mixed fabric comprising CiscoMDS 9700 and 9500 director class switches and CiscoMDS 9148 and 9148S fabric switches,the fabric can have all the switches in the first 32 VSANs. The remaining VSANs include only those switches that supportmore than 32 VSANs.

14 An error message appears in your session if the number of FCNS entries exceeds 20000.15 For platforms other than Cisco MDS 9700, a warning appears in your session if the number of FCNS entries exceeds 10000.16 This value applies to Cisco MDS 9500 with Supervisor 2A. Thus, this limit applies to a fabric comprising of these switches

and Cisco MDS 9700.17 An error message and syslog appear in your session if the total number of zones exceeds 16000.18 For platforms other than Cisco MDS 9700, a warning appears in your session if the number of zones exceeds 8000. However,

further configurations are not blocked.19 Without Smart Zones and for optimal hardware resource usage, configure 1 initiator and 1 target device per zone. The

recommended maximum limit is 50 members per zone.

From Cisco MDS NX-OS Release 8.4(2), Smart Zones support a maximum of 250 members per zone only when the zonemembers are configured as initiators or targets.

20 An error message and syslog appear in your session if the total number of the unique zone members exceeds 32000.21 For platforms other than Cisco MDS 9700, a warning appears in your session if the number of unique zone members exceeds

16000.

5

22 An error message appears on your session if the zone database size exceeds 3.8 MB.23 2000 IVR zones are available across all VSANs. However, a single VSAN must not have more than 1000 IVR zones.24 A system message appears in your session when the supported configuration limit of CFS peers is exceeded.

If there are any switches in the fabric running Cisco MDS NX-OS 6.2(5) or earlier releases, the previous 2-MB zone databaselimit prevails and the new zone scale enhancements are not available. We recommend that the 2-MB zone database limit doesnot exceed, unless all the switches in the fabric run on Cisco MDS NX-OS Release 6.2(7) or later.

Note

Example: Checking the Size of the Zone DatabaseThe following example shows how to check the size of the zone database in VSAN 310:

(config)# show zone status vsan 310 | Inc "Db Size" P 1

Full Zoning Database :Db Size: 1040524 Bytes

--Active Zoning Database :

Db Size: 962156 Bytesc

Now, Add 962156 with 1040524 = 2002680

2002680 / (1024 * 1024) = 1.9 MB.

This database size does not include the pending changes in a session.Note

Configuration Limits for Port Line Rate Throughput on Cisco MDS 9700 40Gbps 24-Port FCoE ModulesFor ports to operate at full-line rate on Cisco MDS 9706, MDS 9710, and MDS 9718 switches, the switch should have a specificconfiguration. The following table lists the maximum number of line rate ports for given Cisco MDS 9700 switch configurations.

Table 3: Line Rate Limitation for Cisco MDS 9700 Series Switches Using Cisco MDS 9700 40 Gbps 24-Port FCoE Module

Maximum No. of Ports/SpeedFront Panel FCoE Bandwidth/SlotNo. of Fabric Cards

16 ports/40 Gbps660 Gbps3

20 ports/40 Gbps880 Gbps4

24 ports/40 Gbps1100 Gbps5

6

If the number of ports that you configure exceeds the maximum limit for the number of ports, it results in all ports operatingin oversubscribed mode.

Note

Fibre Channel Topology Combinations and ScalingFrom Cisco MDS NX0-OS Release 6.2(7), the following configurable features that support scale enhancements are supported:

• Fibre Channel Name Server (FCNS) bulk notification

• Coalesce switch Registered State Change Notification (SW-RSCN)

For more information about the FCNS and SW-RSCN features, see the Cisco MDS 9000 Series NX-OS Fabric Configuration Guideand the Cisco MDS 9000 Family Command Reference documents.

In multidimensional scale configurations, supervisors with 1-GB memory may experience the system manager hap-reseterror.

Note

The following table provides the configuration limits with and without the FCNS and SW-RSCN optimizations.

Table 4: Fibre Channel Topology Combination and Scaling

Scale OptimizationsConfiguration LimitsCoalesceSW-RSCN

FCNS BulkNotification

Scale Topology

EnabledMDS NX-OS Release 6.2(7) and laterOnOnCisco MDS NX-OS Release6.2(9) and later on Cisco MDS9700 Series-only Fabric FLOGI per module: 1000

FLOGI node: 4000

FCNS: 20000

Zone: 16000

Zone members: 32000

Disabled (Disabled bydefault in CiscoMDSNX-OS Release6.2(7))

MDS NX-OS Release 6.2(5) and earlierOffOff

FLOGI per module: 500

FLOGI node: 2500

FCNS: 10000

Zone: 8000

Zone members: 16000

7

Scale OptimizationsConfiguration LimitsCoalesceSW-RSCN

FCNS BulkNotification

Scale Topology

Enabled or disabledFLOGI per module: 400

FLOGI node: 2000

FCNS: 10000, 13000 26

Zone: 8000, 10400 27

Zone members: 16000, 20800 28

On or offOn or offCisco MDS NX-OS Release6.2(9) and later onMDSMixedFabric25 (Cisco MDS 9700Series, 9500, 9250i, 9222i, and9148)

25 The scale enhancements introduced in Cisco MDS NX-OS 6.2(7) and later are available on Cisco MDS 9700 Series Switches(only networks with CiscoMDSNX-OSRelease 6.2(7) and later, running on all the switches and the configurable optimizations):FCNS bulk notification and RSCN coalesce enabled. These enhancements are not available in mixed fabrics regardless ofwhether FCNS and RSCN are enabled. In Cisco MDS NX-OS Release 6.2(9) and later, FCNS bulk notification is enabled bydefault. (To disable FCNS bulk notification, use the fcns no-bulk-notify command.) Coalesce SW-RSCN is disabled by default.

26 This increase in scale is applicable only to the Cisco MDS 9500 Series Supervisor-2A Module.27 This increase in scale is applicable only to the Cisco MDS 9500 Series Supervisor-2A Module.28 This increase in scale is applicable only to the Cisco MDS 9500 Series Supervisor-2A Module.

Fibre Channel Scale LimitationsThe various Fibre Channel scale limitations are described in this section.

Limitation 1

From Cisco MDS NX-OS Release 6.2(7), the fcns bulk-notify and rscn coalesce swrscn vsan commands are available on all CiscoMDS switches. We recommend that you use these commands only on Cisco MDS 9700 Series switches with 48-port 16-Gbps FibreChannel switching module because the higher configuration limits are currently not supported on any other MDS platform.

The FCNS bulk notification and Coalesce SW-RSCN features are supported only in NX-OS Release 6.2(7) and later releases.Enable the Coalesce SW-RSCN only if all the switches in a fabric are Cisco MDS switches that are running Cisco MDSNX-OS Release 6.2(7) or later.

Note

Limitation 2

The maximum zone database size is increased from 2 to 3.8 MB in Cisco MDS Release 6.2(7) and later for all MDS 9700 Seriesswitches to enable zone scale enhancements. The new limit of 16000 zones is supported only on the Cisco MDS 9700 only fabric.Fabrics with Cisco MDS 9500, 9200, or 9100 Series switches continue to have the 2-MB zone database limit, supporting only up to8000 zones.

Limitation 3

In a three-node serial topology, traffic imbalance may occur if the number of port channels that are configured between the switchesare the same. We recommend that you have a single port channel between two switches with any number of member ports. If youconfigure more than one port channel, ensure that the count of port channels between the switches varies.

8

Limitation 4

Themaximum latency (round-trip time) and the packet-drops that are supported on FCIP links are 250 ms and 0.05 percent receptively.

The maximum limit is the same regardless whether latency and packet drop conditions exist together or only one of theconditions exists.

Note

Syslog and Warnings for Fibre Channel Network ScaleThe following table lists the syslogs and warnings for the Fibre Channel network.

Table 5: Syslogs and Warnings for the Fibre Channel Network

Cisco MDS 9500, 9200, and 9100Cisco MDS 9700 SeriesSyslog and Warnings

8000 zones – Hard limit: Syslog warning that states nomore zones can be configured:

“Maximum configurable zonelimit of 8,000 reached.Creation of any more zonesis not supported.”

10400 zones – Hard limit for Cisco MDS 9500 SeriesSupervisor-2A Module: Syslog warning that states nomore zones can be configured:

“Maximum configurable zonelimit of 10,400 reached.Creation of any more zonesis not supported.”

16000 zones – Hard limit: Syslog warning thatstates no more zones can be configured:“Maximum configurable zonelimit of 16,000 reached.Creation of any more zonesis not supported.”

Zone limit

9

Cisco MDS 9500, 9200, and 9100Cisco MDS 9700 SeriesSyslog and Warnings

10000 FCNS entries – Soft limit: Syslog warning aboutvalidated limit:

“Number of Name-Server entries hasreached the maximum validated limitof 10,000. Any more entries couldpotentially destabilize the fabric.”

13000 FCNS entries – Soft limit for Cisco MDS 9500Series Supervisor-2A Module: Syslog warning aboutvalidated limit:

“Number of Name-Server entries hasreached the maximum validated limit of 13,000.

Any more entries could potentiallydestabilize the fabric.”

20000 FCNS entries – Hard limit: Syslog warning:

“Maximum Name-Server entrylimit of 20,000 reached.No more entries are supported.”

20000 FCNS entries – Hard limit: Syslogwarning stating that no more name serverentries are supported:

“Maximum Name-Server entrylimit of 20,000 reached.No more entries are supported.”

FCNS limit

Switch-Level Configuration Limits for Fibre Channel over EthernetSystem messages are generated whenever the configuration limits are exceeded. For more information, see the Cisco MDS 9000Series and Nexus 7000 Series NX-OS System Messages Reference document.

The following table lists the switch-level configuration limits for Fibre Channel over Ethernet (FCoE) on Cisco MDS.

Table 6: Switch-Level Configuration Limits for FCoE

MDS 9710 with 48-Port 10-Gigabit FCoEFeature Name

256FLOGIs per Port

1000FLOGIs per Module

4000FLOGIs per Switch

80VSAN

80VSAN-VLAN Mapping

128 virtual fibre channel port channel and a maximum number of 16members in one virtual fibre channel port channel

Virtual Fibre Channel Port Channel and Member Ports

10

Fabric-Level Configuration Limits for Fibre Channel over IPThe following table lists the fabric-level configuration limits for Fibre Channel over IP (FCIP):

Table 7: Fabric-Level Configuration Limits for FCIP on Cisco MDS 9250i Multiservice Fabric Switch

Cisco MDS 9250i Multiservice Fabric SwitchFeature Name

250-ms round trip and 0.05% packet dropMaximum latency (round-trip time) and packet drops supported on FCIP links

Table 8: Fabric-Level Configuration Limits for FCIP on Cisco MDS 9700 Series Multilayer Directors with Cisco MDS 24/10-Port SAN Extension Module

Cisco MDS 9700 Series Multilayer Directors with Cisco MDS24/10-Port SAN Extension Module

Feature Name

250-ms round trip and 0.05% packet dropMaximum latency (round-trip time) and packet dropssupported on FCIP links

Fabric-Level Configuration Limits for Fibre Channel over Ethernet (FCoE)on MDS 9700 SeriesThe following table lists the fabric-level configuration limits for the Fibre Channel over Ethernet (FCoE) on MDS 9700 Series.

Table 9: Fabric-Level Configuration Limits for FCoE on MDS 9700 Series Switches

MDS 9700 Network with 48-Port 10-Gigabit Fibre Channel overEthernet Module

Feature Name

16000Zones

32000Zone members

1000Zone sets

3.8 MB 29Zone database size

20000Number of FCNS entries in a network

12000Device alias

29 An error message appears in your console if the zone database size exceeds 3.8 MB.

11

• A warning appears in your console if the number of zones exceeds 8000. However, further configurations are not blocked.

• An error message appears in your console if the total number of the unique zone members exceed 16000.

• From Cisco MDS NX-OS Release 6.2(7), a zone's database size is increased from 2 to 3.8 MB, to provide zone scaleenhancements. However, if there are any switches in the fabric that are running Cisco MDS NXOS Release 6.2(5) orearlier, the previous 2-MB zone database limit prevails and the new zone scale enhancements are not available. Werecommend that the 2-MB zone database limit does not exceed, unless all the switches in the fabric run Release 6.2(7)or later.

• An error message appears in your console if the number of FCNS entries exceeds 10000.

Note

Example: Checking the Size of the Zone DatabaseThe following example shows how to check the size of the zone database in VSAN 310:

(config)# show zone status vsan 310 | Inc "Db Size" P 1

Full Zoning Database :Db Size: 1040524 Bytes

--Active Zoning Database :

Db Size: 962156 Bytesc

Now, Add 962156 with 1040524 = 2002680

2002680 / (1024 * 1024) = 1.9 MB.

This database size does not include the pending changes in a session.Note

Cisco MDS 9000 I/O Accelerator Configuration LimitsThe following table lists the Cisco MDS 9000 I/O Accelerator configurations and the corresponding limits.

Table 10: Cisco I/O Accelerator Configuration Limits

MSM-18/4 or SSN-16 Module on MDS 9222i and MDS 9500Modular Chassis and MDS 9250i Fabric Switch, 24/10-Port SANExtension Module on MDS 9710 Chassis

Parameter

4Number of switches in a cluster

16Number of clusters per switch

34Number of switches in a SAN fabric for FC-Redirect

128Number of hosts per target

12

MSM-18/4 or SSN-16 Module on MDS 9222i and MDS 9500Modular Chassis and MDS 9250i Fabric Switch, 24/10-Port SANExtension Module on MDS 9710 Chassis

Parameter

128Number of concurrent flows per Cisco MDS 9000 I/OAccelerator service engine

128 - Release 4.2(1) on MDS 9222i and MDS 9500

512 - Release 4.2(7) or later on MDS 9222i and MDS 9500

512 - Release 6.2(5) or later on MDS 9250i

512 - Release 8.2(1) or later on MDS 9710

Number of flows per Cisco MDS 9000 I/O Acceleratorservice engine (hard limit)

64 - Release 4.2(1) on MDS 9222i/MDS 9500

256 - Release 4.2(7) or later on MDS 9222i/MDS 9500

256 - Release 6.2(5) or later on MDS 9250i

If initiators or targets participating in Cisco MDS 9000 I/OAccelerator are present on MDS 9250i switches, the limit is203 for tape and 160 for disk.

Note

256 - Release 8.2(1) or later on MDS 9710

Number of flows per Cisco MDS 9000 I/O Acceleratorservice engine (soft limit)

1024 - Release 4.2(7d)

1248 - Release 5.2(6b) or later

Number of flows in a cluster

Fibre Channel Flow Configuration LimitsThe following table lists the Fibre Channel flow configurations limits.

Table 11: Fibre Channel Flow Configuration Limits

Flow Statements per ModuleAggregate Flow and Flow Statistics LimitCisco MDS Device

10241000Generation 1Modules

20482000Generation 2Modules

512512Generation 3Modules

512512Generation 4Modules

512512Generation 5Modules

13

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