Linux 2.2.5 also has an implementation for RAID0, RAID1 and RAID5. This is the multiple device driver (md). This design claims to be a device as it occupies a major number but the actual implementation is a hack in ll_rw_block() code. md does mapping of requests from the md device to the actual device so the actual request never reaches the md device[1].
Another approach to the efficient storage management is Hierarchical Storage Management (HSM). It is a scheme that uses secondary storage (disks) and tertiary storage (tapes) for data storage and retrieval. This design does not apply to our system as we only consider disks.
Work on TSS was carried out on Solaris by M. Nitin [3] (RAID1+5) and Suresh N[4] (also cRAID5). A study of the issues in moving TSS to Linux and a prototype implementation was carried out by Pankaj Risbood[5]. The combined work has been reported in [2].