How do I know when to safely remove the subdisk from a diskgroup ?

[Mahesh_Gurugunt]

I have a diskgroup with 2 subdisks (essentialy 2 LUNS). One LUN with 600GB and another of 400GB concatenated. One of the applications on that machine is being moved, as a result we don't need that much space now.

As of now, out of 1 TB space (600+400GB), only 280GB is used. I am planning to remove the 400GB subdisk/LUN. How do I know the if there is any data written to this 400GB? and what is the safe way of removing this subdisk from the existing diskgroup, of course withough loosing data.

Thanks

[Ilya_Voronin]

Try this command. Shows which volumes uses specified disk.
# vxprint -e "any v_plex.pl_sd.sd_da_name=\"${DISK}\"" -v -F %name
(${DISK} is disk name from vxdisk list output).