Data Degradation - Best Form of Media to Prevent it?

Hardware Other Hardware
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Simple question? Which form of media is best to use to prevent data degradation? I know it is definitely not HDD’s and flash-based storage, so what is it? I’ve tried looking around for a definitive answer, and came up empty handed.

Thanks :slight_smile:

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For cold storgae and hot?

Cold storage: Archive grade dvds or archive tapes depending on the budget

Hot storage: Some kind of ZFS cluster with a backup to a offsite storage

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There is no end all answer to this.

It depends on your goal. Tape has a long shelf life if stored properly, but as soon as the temps leave the ideal range, you’re boned.

@Dje4321 is more or less correct.

DVD and BluRay have a long shelf life and are acceptable for archiving small amounts of data. If you really want data safe, you’d want to follow the 3-2-1 rule: 3 separate copies, across two different medias, one offsite.

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The approach that I’m taking for now is

  • Primary ZFS pool (p)
  • rsynced to a RAID6 Synology array
  • Critical data rsynced to a WD Black 4TB and held offline.

In the future -

  • Adding a Secondary replication ZFS pool — (s) to the primary
  • Adding another Primary-prime (p') ZFS pool, replicating to Secondary-prime (s')

We will therefore have

p --------> replicate to -----> s
   |
   \------> rsync to Synology RAID6

   |
   \------> rsync to p'

p' -------> replicate to -----> s'

This may seem OTT, but it will let you maintain your data in a HA-type setting; caveat and downside is that any corruption that isn’t due to ZFS’s CoW nature, primarily say user-error, malicious alteration by third-parties, will get carried “down-stream”.

You would want to maintain a certain time-window before say syncing to (p') and leverage snapshots for any disaster recovery. It wouldn’t hurt to maintain some of these replication targets off-site.