This can happen as a result of the source luns were initialized on an old version of VxVM (for example, pre 5.1SP1 cross-platform disk (CDS) format as well as pre 5.0.1RP3P3 on HP11.31 and 5.0MP3RP3HF2 on Linux) . These versions and above contained the code enhancement, part of which some changes were made in disk geometry calculation.

As a workaround to allow the Storage Migration to take place, the target luns can be initialized with a smaller private region which will result in a larger publen.  For example,

# vxdisksetup -i format= privlen=

However by doing so, it would be important to note this smaller private region as it would need to be taken into consideration in the event of a future diskgroup rebuild.  Please make sure that the diskgroup configuration backup is valid in the /etc/vx/cbr/bk/ directory and the files in that directory are backed up regularly off the host.

When doing Storage Migrations and making use of VxVM mirrors to copy the data from the src disks to target disks, it is important that the publen of the target luns is not smaller than the publen of the source disks. This is especially important if the whole capacity of the source lun is used.

Source luns and target luns may have same geometry specifications and the same can be detected by the Operating System. However VxVM initializes (vxdisksetup –i <disk_name> ) the target lun with a smaller publen as compared to source lun.