On R720xd with H710p I want to delete a VD without reboot. MegaRAID Storage Manager gives me "this is an OS drive" and refuses

Question

I'm trying to reorganize VD on Dell R720xd without reboot.

iDRAC queues VD deletion for reboot time. A hack with installing LSI MegaRAID Storage Manager GUI refuses to delete VD saying "this is an os drive"

The drive is not mounted anywhere.

Answer 1

Turns our I had to delete all signs of partition tables from the VD, mine was GPT so I used gdisk /dev/, then used options

Command (? for help): x

Expert command (? for help): z
About to wipe out GPT on /dev/sdd. Proceed? (Y/N): Y
GPT data structures destroyed! You may now partition the disk using 
fdisk or other utilities.
Blank out MBR? (Y/N): Y

and then MegaRAID Storage Manager finally agreed to delete the VD..

UPD: + it took me some time to find a command for CentOS/RedHat to make fdisk realize the changed size of my /dev/sdd, the command is:

echo 1 > /sys/block/sdd/device/rescan