Perhaps the most interesting thing about the tape verses disk argument…is that there is still an argument. Most storage mediums transition from old to new without even so much as a fuss as the benefit of new media is clearly understood. However, it seems that tape verses disk continues to be the anomaly. Whereas, many IT professionals see a clear and distinct winner, others do not.
On one hand, there is the high speed, highly reliable, random access, online benefit of disk. On the other hand, there is the low speed, low reliability, linear access, offline nature of tape. One is new, fast and flashy. The other is old, slow and cumbersome. The winner is clear, right?
Although the choice may seem clear when looking at the benefit comparison, IT professionals who choose tape for their backup environment will end up citing a couple things like, “tape is still fast enough to meet their window,” or, “their organization can handle extended periods of downtime while waiting on a restore.” However, the most commonly used answer for a tape deployment over disk is that the sheer expense of tape is simply, “cheaper.” With the performance, management and reliability benefit clearly belonging to disk, the outstanding issue seems to be a “perceived” cost issue.
When making a direct cost comparison of media, it is true that the cost-per-byte is cheaper for tape than it is for disk. For some IT professionals, that’s where they draw the line and make a decision. For them, the cost of media is the race, and tape is the winner. The problem, however, has to do with the fact that the race really isn’t about the cost of media; it’s the associated cost of several other factors: downtime, reliability, management, availability, data growth and the cost of the backup system itself. In other words, it’s about the big picture.
It should be noted that some IT professionals have circumvented the whole tape vs. disk decision dilemma and have implemented tiered solutions that use both in concert, otherwise known as Disk-to-Disk-to-Tape (D2D2T). With this approach, IT professionals are writing directly to a disk array for their backup then passing it on to tape for deep archiving and off-site portability. With this approach, organizations are leveraging the many benefits of online disk storage while maintaining the portability and long term retention aspects they are used to receiving with tape.
Download this no-charge 10-minute white paper in its entirety at: http://www.nexsan.com/whitepapers/Nexsan_10min_WhitePaper_Tape_vs_Disk_GA020110-A.pdf
When making the moved toward disk over tape, the DCIG Midrange Array Buyer’s Guide provides the detailed independent analysis important for these decisions. Download the DCIG Midrange Array Buyer’s Guide at no charge and view the results of this comprehensive report at http://www.dciginc.com/2010/06/free-download-dcig-midrange-array-buyers-guide.html
Publish Date: July 1, 2010 6:07 PM