Data Protection
Tape Virtualization
Tape Storage Virtualization
• Problem with tape library management:
– One media server manages one tape library (or one set of drives
in the library)
– Inefficient use of tape resources—drives are often idle
• Tape pooling, or virtualization, solves this problem:
– Tape devices are virtualized—just like disk storage
– Multiple media servers can manage the same set of drives
Without Tape Pooling With Tape Pooling
So the last little bit is on tape. There are 2 ways we can do tape virtualization.
One is to use tape pooling. So without tape pooling each media server would
have its own bank of drives. So, in that case, this one could be really busy
while these ones are sitting idle and we have no way of accessing or using
them.
With tape pooling we create a pool of drives and then any media server could
use any of the drives so we get better utilization. So effectively we are
RAIDING tape. But remember if you RAID tape remember that all drives and
all tapes would have to be available to actually do your recovery. So if you
stripe across too many drives and too many tapes the probability of recovery
becomes lower.