5 ms·
I'm not knowledgeable, but some total guesses: 1) As blu-ray is a consumer product its probably manufactured in greater quantities than backup grade tapes, and
by kitcar 13y ago
I'm not knowledgeable, but some total guesses:
1) As blu-ray is a consumer product its probably manufactured in greater quantities than backup grade tapes, and therefore can be had lower in price, and there are more vendors to source them from. Similarly the drives themselves are cheaper.
2) Tapes aren't random access, therefore it's slow and cumbersome to retrieve single files.
- jonny2112 13y ago3) IIRC most tape storage technolgies are closed source. FB has been heavily pushing their open compute project. Using BDs get them past a lot of licensing problems.
- jchendy 13y agoLTO is an open standard: http://en.wikipedia.org/wiki/Linear_Tape_Open http://en.wikipedia.org/wiki/Linear_Tape_Open
- wmf 13y agoI don't think LTO is any more proprietary than Blu-ray.
- protomyth 13y agoand LTO has way less licensing problems than Blu-ray and LTO-6 has a max of 2.5TB. LTO is also guaranteed to to read tapes from 2 generations earlier and write one generation earlier. Blu-ray has no such long term guarantee.
- derekp7 13y agoRe: 1) Looking at the prices on Newegg, 1.5TB(native) LTO5 tapes run about $30.00, so $20 per TB. Write-once BluRay looks to be about $32/TB, and rewriteable is $80/TB. Re: 2) Although it would take an hour or so to search through an entire tape if all the files were written in a single session, normally backup software writes files in sessions containing a few GB. You can seek to a specific session in about 30 seconds average. So if you put about 4GB per session, it would take a max of approx. 30 seconds to read in that session to retrieve a file. So figure about a minute to retrieve any file. Also, LTO5 transfers about 140MB/sec, vs. 6x BDR disks (what I'm seeing for cheap right now) is only 27MB/sec.