We also have Device Virtualization. Disk virtualization which is similar to RAID. We can actually mask the true physical data layer. Tape Virtualization. There are 2 types of tape virtualization – Tape pooling (to get better utilization of tape media assets) and tape library (where the disk subsystem looks like tape). The benefit of this is that our backup software doesn’t see any difference and it still works with it.
Block Virtualization (we ask for a block and it re-directs us to another block) is a more common type of virtualization.
Here we have 3 different locations where we can do virtualization. ⎯ In our host
(an example of a host based virtualization layer would be our Logical Volume Manager or disk manager) ⎯ In our sub-system
(we can perform device virtualization, this could be RAID)
⎯ In our Network (could either be in a switch or an appliance type architecture)