I’ve previously been amused by stories claiming that tape is dead due to disk backup or VTL being able to seamlessly replace tape. However, lately it just sounds like a tiresome broken record. It’s usually accompanied by poorly described comments such as “tape is unreliable” or “tape is slow”. Honestly, do people who make the claims that tape is dead because of the latest backup-to-disk options understand what enterprise tape is? Sure, tape is slow and unreliable if you’re say, looking at DDS for your backups, but step up to enterprise media and the story is quite different.
So the story that’s set me off on this little rebuttal is “Disk Encroaches on Tape Backup’s Territory”. The article includes the following gem:
Consequently, many companies have been on the lookout for a better option. With the steady decline in prices for disk storage, it has become a replacement for tape at some companies. Virtual Tape Libraries (VTLs), which mimic tape backup systems while storing information on disk, deliver the robust features found with a tape backup system while eliminating tape’s shortcomings.
This conveniently leaves off the rather obvious point of – if your building is on fire and you have 30 seconds to spare, you might be able to run into the computer room and pull out the most recent tape, but I challenge you to pull out your VTL in that time.
More realistically though, you can offsite your media in a regular fashion, but you can’t offsite VTL or disk backup. Yes, you could position these devices offsite, connected by say, dark fibre, but what then happens if that site catches on fire? Yes, you could then replicate the VTLs or disk backup units between that site and another site, but what (a) how expensive will that be, and (b) what happens if corruption is introduced? For true safety, you need to know that at least one of your backups is not only offsite, but also offline.
I’m not dismissing either disk backup or VTL – both have a valid and in fact very important role to play in most enterprise backup solutions. However, the ongoing need to parrot that “tape is dead” is not only inaccurate, but tiresome.