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Been using snapraid for years, it's very flexible and perfect for my needs, with mostly static data on a home server. The greatest thing about it is that you c

Been using snapraid for years, it's very flexible and perfect for my needs, with mostly static data on a home server. The greatest thing about it is that you can just add more storage whenever you want, without having to resilver the whole array. Also if one drive fails, the data on the other drives is still completely accessible. Having said that, I've never had a drive fail without warning (had some that started to go bad, but I've replaced them in the array before they became inaccessible), so I still haven't had to use the data recovery aspect of it yet. I did test recovering a deleted file and that worked though. The downside is that you can only recover to your last snapshot, so it's up to you to set up a schedule or remember to sync the array often.

actionfromafar 4y ago
I wonder how it compares to https://www.greyhole.net/ https://www.greyhole.net/ which is what I use. It can also just have a bunch of drives added to it.
- brokenmachine 4y ago
  From a very cursory look at just the main page you linked, it seems that with greyhole you configure it to store a certain number of copies of each file? On snapraid you have one or multiple parity drives for the whole array, and the parity drives have to be larger than the largest data drive you have (although you can use split parity, where a single parity volume is split over multiple physical drives). So greyhole seems a bit more flexible in this regard. Greyhole does seem to share some of the limitations of snapraid though, "storing files that change often, especially large files, is asking for trouble. i.e. don't use a Greyhole share for your currently-downloading torrents". Snapraid is the same in this regard - it throws errors if files are being written to when it's syncing. So they sound fairly similar.
- leetnewb 4y ago
  Greyhole is a clever pooling strategy on an arbitrary set of drives (comparable to MergerFS). SnapRAID is a parity construction strategy on an arbitrary set of drives, and has the side effect of being able to detect and correct bitrot in data. It is pretty common to pair MergerFS with SnapRAID.
  - brokenmachine 4y ago
    Can you not scrub the data with greyhole? That's a pretty big difference if it doesn't. A big part of snapraid is you regularly do a scrub, and it checks the blocks for errors, which could also alert you to a failing drive. By default I think it checks 10% of the array every time.
    - leetnewb 4y ago
      It looks like greyhole added a checksum checksum verification feature (see line 90 here: https://github.com/gboudreau/Greyhole/blob/master/USAGE https://github.com/gboudreau/Greyhole/blob/master/USAGE). I don't know whether it offers the ability to heal bad copies from good.

actionfromafar 4y ago

I wonder how it compares to https://www.greyhole.net/ https://www.greyhole.net/ which is what I use. It can also just have a bunch of drives added to it.

brokenmachine 4y ago
From a very cursory look at just the main page you linked, it seems that with greyhole you configure it to store a certain number of copies of each file? On snapraid you have one or multiple parity drives for the whole array, and the parity drives have to be larger than the largest data drive you have (although you can use split parity, where a single parity volume is split over multiple physical drives). So greyhole seems a bit more flexible in this regard. Greyhole does seem to share some of the limitations of snapraid though, "storing files that change often, especially large files, is asking for trouble. i.e. don't use a Greyhole share for your currently-downloading torrents". Snapraid is the same in this regard - it throws errors if files are being written to when it's syncing. So they sound fairly similar.
leetnewb 4y ago
Greyhole is a clever pooling strategy on an arbitrary set of drives (comparable to MergerFS). SnapRAID is a parity construction strategy on an arbitrary set of drives, and has the side effect of being able to detect and correct bitrot in data. It is pretty common to pair MergerFS with SnapRAID.
- brokenmachine 4y ago
  Can you not scrub the data with greyhole? That's a pretty big difference if it doesn't. A big part of snapraid is you regularly do a scrub, and it checks the blocks for errors, which could also alert you to a failing drive. By default I think it checks 10% of the array every time.
  - leetnewb 4y ago
    It looks like greyhole added a checksum checksum verification feature (see line 90 here: https://github.com/gboudreau/Greyhole/blob/master/USAGE https://github.com/gboudreau/Greyhole/blob/master/USAGE). I don't know whether it offers the ability to heal bad copies from good.