Backups Aren't Simple

(filipovski.net)

78 points | by afilipovski 5 hours ago

14 comments

  • publlus_enigma 1 hour ago
    There are four times in my life I have suffered regrettable data loss incidents.

    The first was when the telephone pole outside our house was struck directly by lightning. Not only was it the loudest thing I have ever heard, the current surged through the telephone line, into the internal fax modem, and fries everything within its vicinity. I was 10. I did have backuos, but only only floppy and they didn't cover everything.

    The second was storing data in OneDrive - a change to their terms surrounding "lifetime" unlikely noted storage, combined with a client that was unusably slow to download and a deadline for data retrieval meant that I lost most of my files.

    The third was SD card failure in digital camera on holiday, the controller chip died catastrophically, leaving the card completely unrecognised. It was a brand new Sony 128GB card, manufactured by Toshiba, and it seemed to be a common issue. I now shoot to two cards simultaneously.

    And the fourth time was ... Performing a backup. An errant script deleted the source content, but I'd also deleted the existing backup to free up space for the new backup. I've been weary of using rewritable media for some time now as a consequence, but I think backups themselves are high risk activities.

    • Gigachad 2 minutes ago
      >I've been weary of using rewritable media for some time now as a consequence

      I briefly considered using bluray disks as a backup for my photos and other critical docs. But getting a decent bluray burner seems not so easy these days with most production winding down. Next best thing looks like the "object lock" feature on object store services that prevents deleting objects for a certain time.

    • cvhc 59 minutes ago
      > a change to their terms surrounding "lifetime" unlikely noted storage

      I had a similar experience with a Chinese cloud storage provider. They didn't even give a convenient way to export the data. And the client throttled download to like 100KB/s. I luckily was able to parallel download by running the client on several VMs...

      > An errant script deleted the source content, but I'd also deleted the existing backup to free up space for the new backup.

      Sounds like the backup workflow is fundamentally flawed... But I also have the fear that the backup program with root privileges can go off the rails... So I keep my backup job as simple as just running restic with some systemd restrictions.

    • Forgeties79 1 hour ago
      >I now shoot 2 cards simultaneously

      A very lovely change over the last 8 years or so lol. I came up in film during the DSLR revolution. 5D2’s/7D’s/Rebels (i series) years.

      8bit 420 nasty aliasing recording on single cards and praying baby. Magic lantern booted on those same SD’s!

      • jeffbee 23 minutes ago
        Mainstream DSLRs with dual card slots came out 22 years ago.
  • AdieuToLogic 50 minutes ago
    A friend of mine used to work at Veritas[0] making enterprise data retention solutions. When I spoke about their product as being "making backups", he corrected me by saying:

      We are not in the backup business.  We are in the restoration
      business.
    
    0 - https://en.wikipedia.org/wiki/Backup_Exec
    • returningfory2 15 minutes ago
      Correct. In data protection, backup is not the feature. Restore is the feature.
    • voiceofunreason 18 minutes ago
      Backups are boring. Restores, on the other hand, are often exciting.
  • snizovtsev 24 minutes ago
    I'm polishing my backup system right now, and found that `tar | zstd | gpg` plus a small vibe-coded wrapper is pretty much all I need.

    GNU tar has its own incremental index via `--listed-incremental=FILE`. Unlike Borg or Restic, which have their own more complicated repository formats, this leaves me with just one additional file (the `.snar`) alongside a dumb, portable full-disk tar archive.

    The nice part is that, unlike repositories that require both read/write access patterns, tar can compute deltas using only the small `.snar` file, while the main `full-disk.tar` can remain buried in write-only Glacier storage. This makes it a much better fit for Glacier's write-once model and 180-day minimum retention.

    My current plan is to upload a full-disk tar to an external HDD + Glacier on a weekly cadence, and the `.snar`-based deltas daily. That gives me a pretty simple cloud backup solution for a few bucks a month (after burning through $100+ of free credits).

  • chasil 13 minutes ago
    For my Oracle Linux systems, I rely on the vendor ReaR RPM package for the baseline backup. This is similar to the "Ignite" utility that I used in my HP-UX days.

    https://relax-and-recover.org/

    This is two-fold useful, first as it enables boot from backup media for total recovery, second in that it creates a backup.tar.gz that holds everything that was not explitictly ignored in the /etc/rear/local.conf file.

    I'm running Oracle databases on these systems (and the local.conf is configured to ignore the datafile directories). I have standby databases (not Dataguard in that I don't have online redolog replication) that allow me to recover them to the primary in a disaster, with some loss of committed transactions.

    I finally have rsync configured for some scratch temporary files.

    I have dallied with btrfs snapshot replication for home directories (in a loopback mount). My vendor support (via a CSI number) has been on and off, so I don't use btrfs in areas that we need it most.

    My replacements do not like the complexity (and I am retiring).

  • ebrahimh 1 hour ago
    I’m setting up 3-2-1-ish backups for my infra of 3 hosts, and definitely leaning towards Restic + Backrest.

    All my hosts run the same CoreOS setup (https://github.com/ebrahim37/infra-template), where container volumes are placed in one central volumes/ folder and that is the only thing I have to backup.

    I plan to implement it like this:

      vps1:
      - restic container with custom sh entrypoint that will backup volumes/ to homelab every 24 hours
      homelab:
      - backrest container, to back up volumes/, do prune/check, replicate repo to offsite
      - rest-server container, will store backups from vps1, homelab, offsite
      offsite:
      - restic container, backs up volumes/ to homelab every 24 hours
      - rest-server container, store copy of backups from homelab
    
    Only caveat is backing up databases, will either have to do: stop container, backup volume/database-data, start container; or use pg dump etc.

    The deduplication is nice, you can have a snapshot for each week of the past year without crazy storage cost

    • codys 38 minutes ago
      If your system has a way to take consistent snapshots in the filesystem (btrfs, zfs) or volume manager (lvm2, perhaps with a bit of filesystem support to obtain fs consistency), that can be used to avoid database downtime, if desired.

      https://www.postgresql.org/docs/current/backup-file.html

  • bloomingeek 2 hours ago
    "encrypted, chunk-level deduplicated, GFS-rotated, point-in-time archived, cloud, 3-2-1 backup solution" is now my newest password, no commas. (Don't tell anyone!)
    • rileymat2 2 hours ago
      Change the o in rotated to a 0 and you might have a secure password.
  • darvo31 11 minutes ago
    Yep, backup is a verb, restore is a noun. Testing restores is where the real work begins.
  • gerdesj 1 hour ago
    One of our customers decided to go for off site backups with us - they had been a customer for 15 odd years for other services. Backups are not our core business, its one of the services and I got around to setting them up sooner rather than later.

    Two weeks later they had a fire in one of their huge printing machines which caused quite a lot of direct damage due to heat and rendered a lot of equipment broken due to smoke/fumes. It was also, as it turns out, a week before the first COVID 19 lockdown in the UK.

    Their backups landed on a XFS file system with reflinks enabled. I cloned their repo and fired up NFS with their VMs running on our gear. It took me another hour to spin up another OpenVPN server (CA etc) for them to use and sort out a few other details (coffee doesn't brew itself).

    They ran via VPN out of our data centre for most of the pandemic.

    That was an utter triumph but I also have some rather less triumphant stories about backups and lack thereof. Let's skip over those 8)

  • innocent_name 2 hours ago
    >Motivated by our success in developing this solution, we try to use it to backup the homelab with its 10 Docker containers. But later we find out from logs on the individual machines that backups are failing. The reason being that many Docker containers like to create root-owned files, and if you’re not careful you can create a cronjob running as the default user.

    and a privesc also.

    • cvhc 1 hour ago
      Yeah it feels it can be risky to "make the backup also dump the databases, and give it full filesystem permissions on our Docker volumes", depending on what binaries get the root privileges.

      What I do is having a minimal systemd timer under root that only calls restic for backing up files (with some additional systemd seucurity restrictions). App-dependent backup logics, like dumping databases, are done by user/container-level cronjobs separately.

  • readthenotes1 2 hours ago
    "Obviously, none of this is worth anything if you don’t actually test restores."

    One of my teachers claimed that contrary to common behavior, no one actually valued backups; it was restores that were worth paying for.

    • gerdesj 2 hours ago
      Try running a business on that basis - where do the restores come from? 8)

      We charge our customers for backup storage by volume and that includes an annual demonstration of recovery. We fire up some or all of their systems on our gear in isolation and show that they are reasonably functional.

      Your teacher's comment is riffing on the well trod lines of: "heights don't kill people, it's depths that kill people", which is all about perspective. This is is not related to "guns don't kill people ..." which is about agency.

      • al_borland 1 hour ago
        It is true that very few people proactively care about backups. It’s like flossing. People know they’re supposed to do it, but in the moment it feels like a waste of time and energy, when there are more important things to do.

        When data is lost, or decay takes over, the value can skyrocket. Depending on what is lost, someone may be willing to pay 100x when they would have spent on backup in order to get their data back, this is why data recovery services can basically charge whatever they want.

        My assumption is the Venn diagram between people who pass the marshmallow test, and those who proactively backup their systems, has a lot of overlap.

      • OkayPhysicist 2 hours ago
        Running a business on that basis would look like the white(ish)-hat version of ransomware. "Oh, your data is gone? How much is it really worth to you?"
      • bitwize 2 hours ago
        "It's not the fall that kills you, it's the sudden stop at the end."
    • TheCondor 2 hours ago
      It is a special sensation when you go to your hand rolled backup "solution" to make some simple recoveries and start finding problems. It is a complex mix of not dread but disgust, sick to your stomach, self-anger, and loss. I can only image what that's like with like all of your children's baby pictures being the lost material. Borg and restic are fantastic, it still seems like some sort of dummy proof mode might be desirable, all the features in the world and they have some some reasonably sane policy or something that includes verifications.

      On the flip side of that though, really and truly, I've restored a laptop from a timemachine backup and it came back damn nearly identical and that was magical.

      • innocent_name 1 hour ago
        >Borg ... fantastic

        I needed to temporarily move off 20TB from my NAS and bought a Hetzner storage box.

        I wanted to encrypt the data before sending it so i went with the borg ssh mount. Long story short, borg failed a couple of times due to https://github.com/borgbackup/borg/issues/7672, i resumed it per documentation and got 2gb of silently corrupted data. There was no way to do data integrity checks due to broken pipes and there was no option to resume the job from the previous point either. I couldn't afford to go with the s3, backblaze wasn't an option due to placing trust into their proprietary client doing the encryption and i got majorly screwed in the end.

  • senectus1 1 hour ago
    Amazon are finding this out atm :-P

    https://archive.is/Ay7RJ

  • PunchyHamster 2 hours ago
    So is apparently making readable site.

    Software like https://restic.net/ does a good job. Few choices of backend

    Accepts stuff from pipe too so you can just pipe mysqldump or pg_dumpall without intermediate files

    Very decent options for checking repo integrity, personally (well, at work too, we use it on few hundred user machines and servers) I also added "roll a dice for backup and try to restore it" test script to make sure it is working

    Decent deduplication too so "store year's worth of weekly snapshot" is very sensible strategy once you exclude the "constantly changing and useless" (caches etc.) files out of it

    can mount FUSE directory with all backups on sensible OSes.

    https://kopia.io/ does the same +GUI but a bit worse on CLI front (it insists on keeping local config which makes scripting a bit more involved, but not much)

    • LilBytes 1 hour ago
      I'm using Restic & Backrest (https://garethgeorge.github.io/backrest/) everywhere I can, they're both exceptional OSS.

      IMHO, the easiest way to perform a restore test is to use your production backups to refresh a lesser environment on a weekly cadence. Naturally this has to be appropriate to the type of data you're restoring, e.g., our E2E (end to end) testing environment has been built to the same risk tolerances of production so it's suitable for production data and the PII (Personally Identifiable Information) it hosts. If this isn't in your own risk tolerances, you can still perform the same test but ensure the data from prod is anonymised or alternatively destroyed, and perform a second restore after production restore with the dataset that preceeded it that has no PII data or similar.

      With this the E2E tests confirm the backups are expected and you can tick a box that when shit does eventually hit the fan, data corruption isn't a problem. Normal caveats apply, you must make sure your backups are immutable so they cannot be modified or changed _after_ the tests have been ran.

    • bt1a 2 hours ago
      importantly, does your die have a side that corresponds to a multi-continental cataclysmic natural disaster of magnitude only known unknown to pre-recorded-history
  • Devin3162 51 minutes ago
    [dead]
  • pizzafeelsright 2 hours ago
    I don't want backups. I want synced duplicated data in geographically separated by shared credentials.
    • offmycloud 1 hour ago
      > I don't want backups. I want synced duplicated data in geographically separated by shared credentials.

      If you accidentally delete something, how long does it take for the delete to propagate to all of your geographically separated datacenters? You need some sort of point-in-time snapshots to be able to recover from accidents and silent corruption.

    • layer8 1 hour ago
      Sounds like you are the second type of people mentioned in the article.
    • keithnz 53 minutes ago
      that's not really the same thing, what you are describing is redundancy so failure in one (or more) place doesn't bring the system down. Backups are about preventing data loss. Data loss can happen in many different ways, not just a system crashing and burning. It can be deliberately/accidently done such that it would be sync'd everywhere.