5 ms·

The prices are absurdly high if your use-case is storage of large volumes of data that regularly change. It wouldn't be sensible to use Tarsnap for that, and yo

The prices are absurdly high if your use-case is storage of large volumes of data that regularly change. It wouldn't be sensible to use Tarsnap for that, and you probably want to use one of the bulk backup services instead. Tarsnap makes a lot of sense when you benefit from the encryption and (especially) de-duplication features that it offers. For me, all of my most important personal and business data, from multiple decades, compresses-and-deduplicates down to around 6GiB. Considering the high value of the data I store in it, tarsnap's pricing actually feels absurdly low.

patrec 3y ago
> Tarsnap makes a lot of sense when you benefit from the encryption and (especially) de-duplication features that it offers. Can you provide more detail why you think so? I don't believe there is any use case in which tarsnap makes sense, other than maybe some Plan-C backup solution which you fall back on in the highly unlikely event that neither Plan-A nor Plan-B worked. Concretely, what benefits does tarsnap offer over restic or borg in combination with rsync.net, to make up for the substantial downsides (such as insanely slow restore, complete lack of wetware redundancy or being written in C[1])? [1] https://www.tarsnap.com/bounty-winners.html https://www.tarsnap.com/bounty-winners.html
- gnfargbl 3y ago
  My post was specifically addressing the comments around cost.
  - patrec 3y ago
    No, you specifically claimed that "tarsnap makes a lot of sense" in certain situations. I think that's incorrect and that there are basically no situations where tarsnap makes sense as a primary or even secondary backup solution. Even when completely ignoring costs. This is a strong claim, so it should be easy to provide a counter-example if one exists.
- rssoconnor 3y ago
  I use tarsnap because the asymmetric crypto means I can give my cron job authorization to create backups, but it doesn't have authorization to read or delete(!) backups. This ability is critical to prevent a compromised system from having its data wiped and having all backups wiped as well. I haven't been able to figure out how to do this in any other system. But if someone has a tutorial, I am all ears.
  - rcxdude 3y ago
    Rsync.net can do similar, because of their snapshot system. By default there's no way to delete a snapshot except through the schedule set up (you can write to them and ask if it's necessary for some reason). It doesn't use asymmetric crypto to do this but it's neither necessary not sufficient for the purpose of preventing accidental or malicious deletion of backups https://www.rsync.net/resources/howto/snapshots.html https://www.rsync.net/resources/howto/snapshots.html
    - rssoconnor 3y ago
      Right I've considered that. It is however limited to like 7 snapshots. The thing is that tarsnap deduplicates over arbitrarily long time periods, letting me make arbitrarily long staggered sequences of retained archives. Perhaps I should really reconsider if I really need such long lived archives, but it is hard to bring myself to drop them.
      - rcxdude 3y ago
        You can do the same with rsync, they just charge you for the extra space (the differential space, like with tarsnap) instead of providing them for free (from what I can see the limits in the web UI are like 1000 daily and weekly snapshots, 200 monthy snapshots, 100 quarterly snapshows, and 10 yearly snapshots, which I suspect are arbitrary 'good enough for most' numbers, not some hard limit based on what they can profitably provide). I personally use the direct ZFS option so I can set up the snapshots exactly how I want, but it is extra effort and doesn't provide quite as good a guarantee that they won't be overwritten (it's resilient against a compromise of the server uploading the backups because I've set up scripts that way, but it doesn't protect against compromise of the logic credentials for the VM in the same way).
ilyt 3y ago
That if there was zero other options that offer encrypted backups, but other software offers that too. Many also offer deduplication. And deduplication is less of a needed feature if you dont pay thru the nose for GB

patrec 3y ago

> Tarsnap makes a lot of sense when you benefit from the encryption and (especially) de-duplication features that it offers. Can you provide more detail why you think so? I don't believe there is any use case in which tarsnap makes sense, other than maybe some Plan-C backup solution which you fall back on in the highly unlikely event that neither Plan-A nor Plan-B worked. Concretely, what benefits does tarsnap offer over restic or borg in combination with rsync.net, to make up for the substantial downsides (such as insanely slow restore, complete lack of wetware redundancy or being written in C[1])? [1] https://www.tarsnap.com/bounty-winners.html https://www.tarsnap.com/bounty-winners.html

gnfargbl 3y ago
My post was specifically addressing the comments around cost.
- patrec 3y ago
  No, you specifically claimed that "tarsnap makes a lot of sense" in certain situations. I think that's incorrect and that there are basically no situations where tarsnap makes sense as a primary or even secondary backup solution. Even when completely ignoring costs. This is a strong claim, so it should be easy to provide a counter-example if one exists.
rssoconnor 3y ago
I use tarsnap because the asymmetric crypto means I can give my cron job authorization to create backups, but it doesn't have authorization to read or delete(!) backups. This ability is critical to prevent a compromised system from having its data wiped and having all backups wiped as well. I haven't been able to figure out how to do this in any other system. But if someone has a tutorial, I am all ears.
- rcxdude 3y ago
  Rsync.net can do similar, because of their snapshot system. By default there's no way to delete a snapshot except through the schedule set up (you can write to them and ask if it's necessary for some reason). It doesn't use asymmetric crypto to do this but it's neither necessary not sufficient for the purpose of preventing accidental or malicious deletion of backups https://www.rsync.net/resources/howto/snapshots.html https://www.rsync.net/resources/howto/snapshots.html
  - rssoconnor 3y ago
    Right I've considered that. It is however limited to like 7 snapshots. The thing is that tarsnap deduplicates over arbitrarily long time periods, letting me make arbitrarily long staggered sequences of retained archives. Perhaps I should really reconsider if I really need such long lived archives, but it is hard to bring myself to drop them.
    - rcxdude 3y ago
      You can do the same with rsync, they just charge you for the extra space (the differential space, like with tarsnap) instead of providing them for free (from what I can see the limits in the web UI are like 1000 daily and weekly snapshots, 200 monthy snapshots, 100 quarterly snapshows, and 10 yearly snapshots, which I suspect are arbitrary 'good enough for most' numbers, not some hard limit based on what they can profitably provide). I personally use the direct ZFS option so I can set up the snapshots exactly how I want, but it is extra effort and doesn't provide quite as good a guarantee that they won't be overwritten (it's resilient against a compromise of the server uploading the backups because I've set up scripts that way, but it doesn't protect against compromise of the logic credentials for the VM in the same way).

ilyt 3y ago

That if there was zero other options that offer encrypted backups, but other software offers that too. Many also offer deduplication. And deduplication is less of a needed feature if you dont pay thru the nose for GB