Cannot Use All of the Remaining Capacity on a Sun StorEdge 6000 or 2500 Arrays to Create a Volume.

Asset ID:	1-71-1007871.1
Update Date:	2014-10-03
Keywords:

Solution Type Technical Instruction Sure

Solution 1007871.1 : Cannot Use All of the Remaining Capacity on a Sun StorEdge 6000 or 2500 Arrays to Create a Volume.

Applies to:

Sun Storage 6580 Array - Version All Versions and later
Sun Storage 6780 Array - Version All Versions and later
Sun Storage 2540 Array - Version Not Applicable and later
Sun Storage 2530 Array - Version Not Applicable and later
Sun Storage 2510 Array - Version Not Applicable and later
All Platforms

Goal

When examining the details of a Vdisk in either CAM (Common Array Manager) or CLI, the maximum volume size available may be smaller than the difference between the total capacity and remaining capacity. For example, total capacity = 500Gb, configured capacity 200Gb, but the maximum volume size is only 100Gb.

Solution

The value of Maximum Volume Size is dependent upon the amount of contiguous space in a Vdisk.

If an array has been in use for a while and volumes have been deleted, it is possible that the amount of unused capacity is fragmented. The largest contiguous fragment is what will be listed for the maximum volume size.

This can be observed from either the CAM or CLI:

GUI:

Login to the Common Array Manager Host.
Select an Array.
Select Virtual Disks in the Navigation Tree on the left side.
Compare the Total Capacity, Configured Capacity and Maximum Volume Size columns.

CLI

Login to the Management Host and run the following commands:
sscs list array (to see all the arrays managed by this host)
sscs list -a <array_name> vdisk (to see all the Vdisks on this array).
sscs list -a <array_name> vdisk <vdisk_#> to see the details of this particular vdisk.
Compare the Total Capacity, Configured Capacity and Maximum Volume Size values.

If the maximum volume size value is less than the difference between the total capacity and configured capacity, that Vdisk needs to be defragmented in order to recover the multiple fragments into a single contiguous space. Defragmenting a Vdisk can be done on a live system but it will have a performance impact similar to a volume reconstruction of the array. Defragmenting a Vdisk can be done from either the CAM or the CLI. This operation can only be performed on an optimal Vdisk. If multiple Vdisks require defragmentation, a separate job will be created for each one. Disable disk scrubbing for all volumes associated with the Vdisk at least 12 hours prior to starting a defragmentation. This will allow any existing jobs to complete.

For detailed information on defragmentation, see <Document 1614831.1> Sun Storage 2500, 2500-M2, and 6000 Arrays: How Virtual Disk (VDisk) Defragmentation Works

GUI:

From the Volume Details page, disable Disk Scrubbing by changing Enable to False and saving.
Select the Vdisk to get to its Vdisk Details screen.
Select defragment.
Progress can be monitored by selecting Jobs and the particular defragment job.
When defragmentation is complete, re-enable Disk Scrubbing for those volumes it was disabled in step 1.

CLI

scsi modify -a <array_name> -k disable volume <volume_#>
sscs modify -a <array_name> -f vdisk <vdisk_#>
Progress can be monitored by listing the job (sscs list -a <array_name> jobs to get the job # then sscs list -a <array_name> jobs <job_ID>).
scsi modify -a <array_name> -k enable volume <volume_#>

References

<NOTE:1614831.1> - Sun Storage 2500, 2500-M2, and 6000 Arrays: How Virtual Disk (VDisk) Defragmentation Works

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