Here is a troubleshooting scenario that we thought would be useful to share.
If you try to deport dg , and meet the following error:
VXVM vxdg ERROR V-5-1-584 Disk Group XXX: Some volumes in the disk group are in use.
First, confirm that the application has stopped.
But ps -ef can see many application process.
Manually kill all application processes, deport dg , error still.
df -k can see io error entry:
df:/mountpoint :There is an input or output error.
then umount /mountpoint
deport dg again, problem solved.