A "virtual disk" is a RAID array.  If you are seeing 4 for your RAID 5, then you have multiple virtual disks created across the same physical disks (called 'slicing'), so each VD will be listed under Virtual Disks.  If you have a single RAID 1 created using the entire space of two disks, then only one VD will show for RAID 1; if you had 2x500GB disks and created a RAID 1 of 200GB and another RAID 1 of 300GB, then you would have two RAID 1 virtual disks listed.  You can click on the VD to view its member disks.
Have a Raid 1 that one drive died, replaced it, do I need to do anything else , only the original drive is showing in OSMA under the virtual disk. It's been 6 hours, also how would I tell the % it is at if it is rebuilding?  thanks Pat
Degraded Drive replacement in PE2850 with Perc 4e/Di