Hello TeePandu,   Unfortunately there is not an undo option. You cannot use this method to remove disks.   If you have another drive you can do the RAID level migration again RAID0 > RAID5   It may be you need to back up the System VD, Delete the virtual disk, Configure the VD's you want and install/restore from backup.  
I have 4 x 1TB disk installed on PERC H730, and it was configured as RAID 5 with the OS (virtual disk 1) and data (virtual disk 2) on same physical drives. I want to add 2 more HDDs into data that have the same specs with the existing ones to that array without losing any data. I saw many posts that it can be done with "reconfigure" option from OSMA. but when I tried, I can't find that. Is it possible to add the new HDDs to Data Virtual Disk only? If I remove virtual disk 2 (data) and create a new VD, can 2 new HDDs be selected when creating it? Or do I need to delete all VDs to add new HDDs?  [IMAGE]Want to expand D:\[IMAGE]Here is current configuration
Can't find reconfigure option on PERC H730 (RAID 5)