SNAP Shoot Services

Apr 24th, 2009

SNAP Shot Services Quick-start

Aug 2009

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Snapshot Services overview

• Snapshot services provide data protection.• Snapshots allows you to save a volumes data at the time the

snapshot is created.• The maximum number of snapshots is determined by your license. • When the maximum number of snapshots are reached the oldest

snapshot will be deleted. • A task and schedule can only be created when you have a MV.• You can set snap pool thresholds and policies.• A master volume and its snap pool can be in different virtual disks,

but must be owned by the same controller.

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Snap pool and master volume

• You must have a snap pool in order to have a master volume.• The snap pool is created before the master volume.• Master volumes are associated with a snap pool, which contains

pre-allocated reserve space for the snapshot data.• Snapshots can be taken of master volumes only.• A standard volume can be converted to a master volume. • A master volume can only be converted back to a stander volume

via cli. • You can convert a master volume and or standard volume that

contains data.• A snap pool can have 16 master volumes associated with it.• The snap pool and master volume must be owned by the same

controller.

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Creating a Snap Pool• Select Manage > Volume Management > Snapshot Services > Create Snap-

Pool.

• Select the Vdisk and then click “create snap pool”.

• Enter snap pool size and name then click “crate snap pool”

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Create a Master Volume• Select Manage > Volume Management > Snapshot Services > Create

Master Volume.

• Select the virtual disk where you want to create the MV and then select a snap pool, enter size, name and lun if desired then “ create master volume”

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Snap Pool and Master Volume Creation complete

• If your volume type seen as Master, the snap pool and master volume have

been created and are now ready.

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Map Master Volume

• Map your Master Volume to the host.

– Use Volume Management > Volume Mapping menu

• Rescan disks from host side.– If not recognized, check volume mapping. Occasionally need reboot

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Taking a single snapshot• Select Manage > Volume Management > Snapshot Services > Take

Snapshot.

• Select the VD, select the MV, select a name and the take the snapshot

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Scheduler overview

• Scheduler is used to create tasks and define schedules that will be run automatically.

• You have to create a task before you can create a schedule.• Create tasks to take a snapshot, reset a snapshot, or copy a

volume.• A task is create for a specific master volume. If that MV is deleted

you will have to create a new task. The task is associated to the MV serial number.

• If a schedule expires you can use the same task unless the MV has been deleted.

• The prefix numbering can be from 0001 to 9999 before rolling over.

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Setting up a Task.

• Select Manage > Scheduler > Manage Scheduler.

• Follow the steps. Select the type of task. Select the MV you wish to assign the task to. Select the prefix and then the number of snap shots and then the name. Then click create task.

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Adding a schedule• In the Schedules panel click Add New Schedule.

• Select starting time. Then you can select Schedule Recurrence, Time Constant, Data Constraint, Count Constraint and Schedule Expiration. Then select the task and the name of the schedule and click create schedule.

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Task and Schedule Created

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Using snapshot

• You can map new snapshot image to other host for backup or other use

– MS Windows does not allow same signature volume to be mounted twice by its specification/warning, but worth try.

• Use volume mapping menu on storage side– Can use Read-Only or Read-Write enabled.

– Storage maintains original PIT image and updates after mount

• Use disk management on host-side to mount or assign drive letter

• Or you can restore/roll-back master volume from selected snapshot – Can select to include or exclude updated data if that snapshot was

mounted and updated

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Updating a Snapshot by resetting

• Will swap mapped snapshot instantly.

• Before resetting a snapshot you must unmount it from data hosts to avoid data corruption.

• Select Manage > Volume Management > Snapshot Services > Reset Snapshot. Select the VD and the SS to be reset click reset and then a process window will pop up.

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Snap pool polices and Thresholds

• Each snap pool has three policy levels that notify you when the snap pool is reaching decreasing capacity.

• You can set the polices and threshold of a snap pool.

• The default policy levels are Warning, Error and Critical. • Each policy level has a threshold level and policy. • The threshold level for “W” is 75% “E” is 90% “C” is 99%• You can not modify the critical threshold. • When a threshold is reached you will get an event posted and what

ever the policy is the array will execute that policy. • Default police’s are “W” notify only “E” delete oldest snapshot “C”

delete snapshot. These are one for one. • Policies can be modified except for “W” this is all ways “ notify only”• These policies and thresholds are associated with the SP not MV.

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Setting Snap Pool Policies and Thresholds

• You can change the policy and threshold level.

• Warning is notify only and the Threshold is 75% can be changed.

• Error default is Delete Oldest SH. You can select Delete SH, Auto Expand, Halt on Writes and Notify Only. The Threshold is 95% can be changed.

• Critical default is Delete SH. You can select Halt Writes and Delete Oldest SH. The threshold is 99% and can not be modified.

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CLI Commands for Snapshots

• Show snap-pools will show the snap pools, policies and Thresholds

• # show snap-pools• Vdisk Serial# Name• Size Free MasterVols Snapshots• -------------------------------------------------------------------------• snap_test 00c0ff0a6aab0048efaee44901000000 snap_test_SP1• 2500.0GB 2499.9GB 1 18• Threshold %Usage Policy SizeToExpand• ---------------------------------------------------------• Warning 75% Notify Only N/A• Error 90% Delete Oldest Snapshot B• Critical 99% Delete Snapshots N/A

• 58558_snap 00c0ff0a6a7f0048bbdaf14901000000 58558_snap_SP1• 1000.0GB 999.9GB 1 19• Threshold %Usage Policy SizeToExpand• ---------------------------------------------------------• Warning 75% Notify Only N/A• Error 90% Delete Oldest Snapshot B• Critical 99% Delete Snapshots N/A

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CLI Continued

• Show snapshoots will list all snapshots

• Show master-volumes will list the MV

• Delete all-snapshots deletes all snapshots associated with a specified volume. This option is only available in cli.

• Delete all-master-volumes you must delete all snapshots before deleting the MV

• Delete snap-pools you can only delete one snap pool at a time.

• For more detailed CLI command check the CLI reference guide