310 Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1
Example 7-31 shows the use of the migratetoimage command to migrate the data from 
volume_A onto mdisk10, and to put the MDisk mdisk10 into the STGPool_IMAGE storage pool.
Example 7-31   The migratetoimage command
IBM_2145:ITSO_CLUSTER:superuser>migratetoimage -vdisk volume_A -mdisk mdisk10 -mdiskgrp 
STGPool_IMAGE
7.8.18  Shrinking a volume
The shrinkvdisksize command reduces the capacity that is allocated to the particular 
volume by the specified amount. You cannot shrink the real size of a thin-provisioned volume 
to less than its used size. All capacities (including changes) must be in multiples of 512 bytes. 
An entire extent is reserved even if it is only partially used. The default capacity units are 
MBs.
You can use this command to shrink the physical capacity of a volume or to reduce the virtual 
capacity of a thin-provisioned volume without altering the physical capacity assigned to the 
volume. Use the following parameters to change volume size:
/SM590000For a fully provisioned volume, use the -size parameter. 
/SM590000For a thin-provisioned volume’s real capacity, use the -rsize parameter. 
/SM590000For a thin-provisioned volume’s virtual capacity, use the -size parameter.
When the virtual capacity of a thin-provisioned volume is changed, the warning threshold is 
automatically scaled. 
If the volume contains data that is being used, do not shrink the volume without backing up 
the data first. The system reduces the capacity of the volume by removing arbitrarily chosen 
extent, or extents from those sets allocated to the volume. You cannot control which extents 
are removed. Therefore, you cannot assume that it is unused space that is removed.
Image mode volumes cannot be reduced in size. To reduce their size they must first be 
migrated to fully managed mode. 
Before the shrinkvdisksize command is used on a mirrored volume, all copies of the volume 
must be synchronized.
Shrink the volume by the required amount by issuing the shrinkvdisksize -size disk_size 
-unit b | kb | mb | gb | tb | pb vdisk_name | vdisk_id command.
Important: Consider the following guidelines when you are shrinking a disk:
/SM590000If the volume contains data or host-accessible metadata (for example an empty physical 
volume of a logical volume manager), do not shrink the disk.
/SM590000This command can shrink a FlashCopy target volume to the same capacity as the 
source.
/SM590000Before you shrink a volume, validate that the volume is not mapped to any host objects. 
/SM590000You can determine the exact capacity of the source or master volume by issuing the 
svcinfo lsvdisk -bytes vdiskname command.