Storage virtualization resolves the increasing complexity of managing storage by combining multiple storage devices into a single, logical resource with a single view. The benefit of virtualization is that less-expensive storage can be used to provide enterprise-class functionality.
A virtual storage environment includes virtual tape drives and virtual volumes. Data is written to or retrieved from the tape volume cache rather than physical tape cartridges. This provides tape read and write access at disk speeds.
Hosts attached to a TS7700 are presented with an image of up to 256 virtual tape drives, which emulate the operation of physical tape drives. These virtual tape drives read data from, and write data to, virtual volumes within a tape volume cache. These virtual volumes function as physical volumes, or tape cartridges.
When the TS7700 is attached to a tape library, the TS7700 Server manages the physical tape drives, or physical volumes, in the tape library and controls the movement of data between physical and virtual volumes. The TS7700 Cache temporarily holds data before writing it to tape, caches the data after a read or write operation to provide fast subsequent access, and provides source data when replicating to another cluster in a Grid.
Premigration occurs when a virtual volume is written to a physical volume.
Physical volumes can contain one or more virtual volumes. A physical volume that contains more than one virtual volume is a stacked volume.
Stacked volumes can be configured through policy management into pools, which enable specific workloads to be managed differently for encryption, reclamation, or other tasks.
Data that has been migrated to physical tape may be accessed seamlessly from host applications. A recall occurs when data is moved from physical tape back into the TS7700 Cache.
Today you learned the basics of how the virtual storage works in the TS7700. For additional information, see IBM Knowledge Center and other eLearning modules to learn more.