Comment 1 for bug 2055149

Analysis:
Currently, IBM SVf driver's retype operation runs the below procedure to change the iogrp property of a volume:

Issue the following command: addvdiskaccess – To add the access of the volume to iogrp1
Issue the following command: movevdisk – Move the volume to the new iogrp1 but the volume still has access to iogrp0
Issue the following command: rmvdiskaccess – To remove access from the old I/O group , i.e., iogrp0

In the above process, as soon as the rmvdiskaccess is called, the bootable disk looses access of the VM. Due to this the VM goes into read-only mode as there is no path to the OS disk.

RCA:
This happens because when the volume is shifted to a new iogrp1, the VM needs user intervention to run the discovery of the volume again to create and store the new path for the volume through iogrp1.
After the discovery is completed, and now the VM knows that the OS-volume is access through paths of iogrp0 and iogrp1, only then the rmvdiskaccess should be executed to remove the old path of the old iogrp0.

Currently, our retype operation doesn’t give the user to run discovery for the new iogrp1 of the volume and directly runs rmvdiskaccess.

Resolution:
Part-1: Need to check if the VM has access to iogrp1 or not. If not, then need to first give iogrp1 access to the VM.

Part-2: Need to stop the control before rmvdiskaccess for the user to intervene and run discovery for the new iogrp1 of the volume.

Part-3: Once the discovery is completed need to run the rmvdiskaccess for the old iogrp0 of the volume.