Disk vs. tape, for low-cost storage
What are the advantages of using disk for low-cost storage, as opposed to tape?
There are a number of advantages to using disk over tape. Performance comes to mind first, as some of the faster tape technology is sometimes still slower than low-cost disk. For example, LTO-2 tape drives at 35 MBps native versus approximately 75 MBps for ATA
disk. Another advantage is based on the fact that disk is a random access device ability to provide multiple concurrent mount points. In contrast, tape drives are sequential access devices allowing only a single mount point unless some form of data interleaving is used (at a cost, performance-wise).
On the other hand, disk still presents some challenges when it comes to vaulting. While it is easy and relatively inexpensive to send tape off site, the same cannot be said about disk. The cost of a data replication to a remote location can quickly make a low-cost disk storage solution not so low-cost anymore.
This was first published in August 2004