Using vxresize to shrink a volume and file system onto a subset of disks and reclaim the unused disks
Article ID: 100038844
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Description
Description
This article describes a way to shrink large volume/file system and reclaim unneeded disks.1. It's recommended to run any vxresize commands during periods of lighter I/O activity.
2. Make sure the subset of disks you're shrinking the volume to, when added together, contain enough disk space to hold the shrunken volume/file system.
3. It's recommended to add nohup to the command so that if it takes a while, if your terminal session disconnects, the process won't be interrupted.
4. It's also recommended to background the process by appending & to the command. The -b flag mentioned in the vxresize man page does not always background the command.
5. Make sure the
6. Assuming the file system is of type VxFS, here's the syntax:
nohup /usr/lib/vxvm/bin/vxresize -gwhich will shrink the volume and the file system on it to the specified
7. Note: Only the vxassist portion of vxresize will show up in `vxtask monitor`. However, you're likely to miss it since the vxassist portion can complete very quickly (within a second or two). The fsadm portion of vxresize can takes much longer (possibly hours if the file system is very large) to complete and this portion of vxresize does not show up in `vxtask monitor`. In addition, the file system will not appear be progressively shrinking, so you won't be able to rely on df -k output to monitor progress. The size won't change until fsadm is complete. If you start the command and suspect something is awry, please engage a technical support engineer instead of interrupting the process. Again, it's always recommended to run any vxresize commands during periods of lighter I/O activity.
8. Once the command is complete, verify the volume is entirely on only the disks you wanted to keep it on:
vxprint -htg
Any unused disks will still show up as disk media (dm) within your disk group (since you haven't removed them yet from the disk group), but under the shrunken volume itself, only the disks you specified during the vxresize command will be used by the volume.
9. Once you've verified the disks you want to free up are no longer used by the volume, you can remove them from the disk group:
vxdg -g
10. Once the disks are removed from the disk group, run:
vxdisk -alldgs list
For the reclaimed disks, the DISK and GROUP columns should have only dashes - -
If this is the case, they are free for re-use.
RESOLUTION CRITERIA:
Check the new volume size with vxprint -htg
Issue/Introduction
