Yes, normally you have to do vgreduce before deleting the vdisk in the EVA.
> so what will happen if only deleting vdisk
The disk will disappear from the server so you will get disk failure errors on the server from LVM and maybe from EMS/hardware monitoring. Nothing will happen in the eva8k array.
> for powered off server.
Are you retiring the server and not keeping it in service? Then no need to do anything on the server.
if there was data on the pv refleted to that vdisk you wanted to delete, you would not be able to vgreduce, maybe you could use pvmove to move the data to other pv that was not created on eva8000 first and then vgreduce.
Then there will be a missing disk in that volume group. You can try "vgreduce -f /dev/vgXX" (force vgreduce) when you reuse the server and then vgexport the volume group.
After you lvremove all the lvols that are attached to the disk and then vgreduce the disks out of the group, be sure to run pvremove to clean off the LVM information. That way, the disks are immediately available for another system or VG creation. There is nothing scarier than running pvcreate on a LUN and it says the PV already belongs to a volume group. Before you use the -f option, you usually spend a lot of time trying see if the LUN is really in use.
since you don't need that data on the vg, why not just vgexport the vg and then pvremove the PVs came from vdisks on eva8000? Iã could not figure out how you still need the vg and at the same time you don't need the data stored on the PVs came from vdisks on eva8000. or you could check out using lvdisplay -v to find which lv was on those vdisks and then lvremove thie lv and then vgreduce the vg, it would reach what you want.
