Disk vs Tape Showdown

The extended driving during this Thanksgiving weekend afforded me the opportunity to catch up on podcasts. The November 8th episode of Infosmack featured a “disk vs. tape showdown“. Geoff Barrall, CTO of Overland Storage, discussed his recent presentation at Storage Network World, “Time to Take Another Look at Tape“. I visited this topic in May in the post “Don’t Get Duped by DeDup“.

Barrall reviewed the highlights of his presentation, which in effect, concluded that tape was better than disk in all areas except quicker recovery … i.e., tape offered superiority with accelerating backups, long term archival, lowest cost per gigabyte, sustained shelf life, offsite portability, lower energy consumption, and lower real estate requirements. He drove home the cost differences with an effective – albeit specious – comparison of a 16TB de-duplicating solution with 1.1TB/hour of throughput performance and a price of $220,000 against a 36TB LTO5 24-slot tape system with performance of 1TB/hour at a cost of $6,000.

Barrall took a beating by the show hosts, as the podcast is primarily about disk. And his argument was full of the rhetoric and equivocations typical of the other side, but he made some good points. The biggest takeaway for me was validation for my view that dedup has many advantages, but in most cases they do not outweigh the costs. It was an expensive technology before when it was just Data Domain, but now that EMC bought them, it will only get more pricey as EMC tries to recoup their investment.