7 ms·

Honest question: are tape drives fast enough for use in any asynchronous/random-access environment, or are they generally limited to backups, financial and scie

by piker 9y ago

Honest question: are tape drives fast enough for use in any asynchronous/random-access environment, or are they generally limited to backups, financial and scientific data? For example, could something like Youtube rely on tapes as the tail end of a LRU cache or similar?

jonatron 9y ago
According to https://en.wikipedia.org/wiki/Linear_Tape-Open#Positioning_times https://en.wikipedia.org/wiki/Linear_Tape-Open#Positioning_t... , in the region of 50 seconds, which isn't really good enough.
- LeifCarrotson 9y ago
  I'm sure there's long-tail data on YouTube for which terabytes of files that could be backed up to tape are accessed far more slowly than every 50 seconds. I agree that this would not be a great user experience, but there's certainly a place for it, especially if the cost/terabyte is compelling.
  - jandrese 9y ago
    The other problem is that Hard Drives are cheap as hell and tapes, especially ones loaded into automatic robots, are really not that cheap. It's the perennial disappointment with tape drives that the media has "enterprise" pricing, making it barely better per TB than cheap consumer spinning hard drives.
gwbas1c 9y ago
Probably not for serving user requests for content. But, if Youtube archived the original upload on tape before transcoding to a different format, then it would be useful. The tapes would really only be "read," in a batch manner, when they want to re-transcode to a newer codec. Likewise, tape would be a great way to store the digital equivalent of the "negatives" once a movie, TV show, or music album is complete. No one needs instant, on-demand, random access to every shot, every take, and every camera angle. It can be pulled off the tape in 10 years when producing the Nth remaster for the new super-duper bluray version.
brudgers 9y ago
Tape provides linear access. The limits of AWS Glacier are probably a good place to start back of napkin latency calculations. https://aws.amazon.com/glacier/ https://aws.amazon.com/glacier/

by piker 9y ago

jonatron 9y ago

According to https://en.wikipedia.org/wiki/Linear_Tape-Open#Positioning_times https://en.wikipedia.org/wiki/Linear_Tape-Open#Positioning_t... , in the region of 50 seconds, which isn't really good enough.

LeifCarrotson 9y ago
I'm sure there's long-tail data on YouTube for which terabytes of files that could be backed up to tape are accessed far more slowly than every 50 seconds. I agree that this would not be a great user experience, but there's certainly a place for it, especially if the cost/terabyte is compelling.
- jandrese 9y ago
  The other problem is that Hard Drives are cheap as hell and tapes, especially ones loaded into automatic robots, are really not that cheap. It's the perennial disappointment with tape drives that the media has "enterprise" pricing, making it barely better per TB than cheap consumer spinning hard drives.

gwbas1c 9y ago

Probably not for serving user requests for content. But, if Youtube archived the original upload on tape before transcoding to a different format, then it would be useful. The tapes would really only be "read," in a batch manner, when they want to re-transcode to a newer codec. Likewise, tape would be a great way to store the digital equivalent of the "negatives" once a movie, TV show, or music album is complete. No one needs instant, on-demand, random access to every shot, every take, and every camera angle. It can be pulled off the tape in 10 years when producing the Nth remaster for the new super-duper bluray version.

brudgers 9y ago

Tape provides linear access. The limits of AWS Glacier are probably a good place to start back of napkin latency calculations. https://aws.amazon.com/glacier/ https://aws.amazon.com/glacier/