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Redundant sets of drives... or high density backup tapes. Tape backups have come along with drive size increases: https://en.wikipedia.org/wiki/Linear_Tape-Ope

by pyre 11y ago

Redundant sets of drives... or high density backup tapes. Tape backups have come along with drive size increases: https://en.wikipedia.org/wiki/Linear_Tape-Open#Generations https://en.wikipedia.org/wiki/Linear_Tape-Open#Generations looks like LTO-10 is planned to be 48TB per cartridge.

dragontamer 11y ago
LTO6 is current. LTO7 is "future". LTO8 may never happen, let alone LTO9 or LTO10 (If SSDs prove to be superior to tapes... investments will change for sure.) The chief benefit of LTO is that it still remains the cheapest and does in fact have huge sequential read/write speeds. Random read/write is even worse than discs but for backup purposes, sequential is king.
- pixl97 11y ago
  SSDs may have issues with long term 'disuse', as in you unplug the drive and leave it on the shelf, data loss may occur. With most tapes you can put them in cold storage and they should last decades.
  - acdha 11y ago
    > With most tapes you can put them in cold storage and they should last decades. This is _hopefully_ true but operational history is so full of unpleasant surprises that I would hesitate to trust any type of storage which isn't regularly verified. With previous generations of LTO, a colleague had encountered fun failure modes like the media degrading rapidly (unrecoverable in less than a year) when a tape was stored on its side, which turned out to be an “everyone knows” fact not mentioned anywhere in the tape or drive documentation. A difference coworker had encountered some issues with a batch which had a defective lubricant causing the surface to break down over a couple years. One place we worked with had to carefully de-tune a new tape drive after learning that the old one had drifted out of alignment for at least a year before physically failing, which meant that most of their tapes were no longer readable by a drive in standard calibration. This is not to say that tape doesn't have a place - analogous failures happen for everything else and the cost-per-GB is appealing. I just don't think we actually have a toss-in-on-the-shelf storage media which can be assumed to work over a long term. You can address those issues with a regimented approach for rotation and mixing physical devices, media, and location but that increases the cost of adding a new storage technology into the mix since you need to develop that operational confidence for each class.
    - StillBored 11y ago
      "One place we worked with had to carefully de-tune a new tape drive after learning that the old one had drifted out of alignment for at least a year before physically failing, " This sounds like a story two decades old, LTO and all modern tape drives have servo tracks on the tapes.. AKA the drive realigns itself to the tape track on the fly as the media passes the head. If the drive cannot do this, you get track following check conditions during the write.
      - acdha 11y ago
        That's certainly possible – I thought that was their first generation LTO system but it might have been the previous one which was being replaced. It was a decade ago so both would still have been in service at that time. The main point in mentioning it wasn't to say that tape is terrible but just that each unique class of hardware brings unique challenges which might not be obvious at first until you have a fair amount of operational time. (Thinking about the people who learned the hard way why RAID arrays should mix hard drives across batches and manufacturers)
  - njharman 11y ago
    Yeah but with drives and machines so cheap, most users can keep all their data live, on active drives. Actually on 3 or more drives geographically dispersed.
- merb 11y ago
  We asked Dell for Backup Solutions a while ago, the only thing they told us was that more and more the LTO way of backing up date will decrease and people will focus on offsite cold disk coldstorage. However they forgot that there are customers which don't have many datacenters all over the place...

by pyre 11y ago

dragontamer 11y ago

LTO6 is current. LTO7 is "future". LTO8 may never happen, let alone LTO9 or LTO10 (If SSDs prove to be superior to tapes... investments will change for sure.) The chief benefit of LTO is that it still remains the cheapest and does in fact have huge sequential read/write speeds. Random read/write is even worse than discs but for backup purposes, sequential is king.

pixl97 11y ago
SSDs may have issues with long term 'disuse', as in you unplug the drive and leave it on the shelf, data loss may occur. With most tapes you can put them in cold storage and they should last decades.
- acdha 11y ago
  > With most tapes you can put them in cold storage and they should last decades. This is _hopefully_ true but operational history is so full of unpleasant surprises that I would hesitate to trust any type of storage which isn't regularly verified. With previous generations of LTO, a colleague had encountered fun failure modes like the media degrading rapidly (unrecoverable in less than a year) when a tape was stored on its side, which turned out to be an “everyone knows” fact not mentioned anywhere in the tape or drive documentation. A difference coworker had encountered some issues with a batch which had a defective lubricant causing the surface to break down over a couple years. One place we worked with had to carefully de-tune a new tape drive after learning that the old one had drifted out of alignment for at least a year before physically failing, which meant that most of their tapes were no longer readable by a drive in standard calibration. This is not to say that tape doesn't have a place - analogous failures happen for everything else and the cost-per-GB is appealing. I just don't think we actually have a toss-in-on-the-shelf storage media which can be assumed to work over a long term. You can address those issues with a regimented approach for rotation and mixing physical devices, media, and location but that increases the cost of adding a new storage technology into the mix since you need to develop that operational confidence for each class.
  - StillBored 11y ago
    "One place we worked with had to carefully de-tune a new tape drive after learning that the old one had drifted out of alignment for at least a year before physically failing, " This sounds like a story two decades old, LTO and all modern tape drives have servo tracks on the tapes.. AKA the drive realigns itself to the tape track on the fly as the media passes the head. If the drive cannot do this, you get track following check conditions during the write.
    - acdha 11y ago
      That's certainly possible – I thought that was their first generation LTO system but it might have been the previous one which was being replaced. It was a decade ago so both would still have been in service at that time. The main point in mentioning it wasn't to say that tape is terrible but just that each unique class of hardware brings unique challenges which might not be obvious at first until you have a fair amount of operational time. (Thinking about the people who learned the hard way why RAID arrays should mix hard drives across batches and manufacturers)
- njharman 11y ago
  Yeah but with drives and machines so cheap, most users can keep all their data live, on active drives. Actually on 3 or more drives geographically dispersed.
merb 11y ago
We asked Dell for Backup Solutions a while ago, the only thing they told us was that more and more the LTO way of backing up date will decrease and people will focus on offsite cold disk coldstorage. However they forgot that there are customers which don't have many datacenters all over the place...