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Backups Aren't Simple

117 pointsby 7h agofilipovski.net
55 comments
4h agoHN ↗

"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.

4h agoHN ↗

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.

3h agoHN ↗

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.

4h agoHN ↗

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.

4h agoHN ↗

"It's not the fall that kills you, it's the sudden stop at the end."

4h agoHN ↗

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?"

3h agoHN ↗

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.

4h agoHN ↗

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)

4h agoHN ↗

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

3h agoHN ↗

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.

4h agoHN ↗

"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!)

4h agoHN ↗

Change the o in rotated to a 0 and you might have a secure password.

4h agoHN ↗

I don't want backups. I want synced duplicated data in geographically separated by shared credentials.

3h agoHN ↗

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.

3h agoHN ↗

Sounds like you are the second type of people mentioned in the article.

2h agoHN ↗

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.

4h agoHN ↗

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.

3h agoHN ↗

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.

3h agoHN ↗

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)

3h agoHN ↗

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.

3h agoHN ↗

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!

2h agoHN ↗

Mainstream DSLRs with dual card slots came out 22 years ago.

1h agoHN ↗

Sadly after 22 years, it's still considered a "high-end" feature. Even on $1600 Fujifilm x100vi, there is still single SD slot.

1h agoHN ↗

I would hope they have some feature for automatic backup to your phone over bluetooth or such today.

1h agoHN ↗

WiFi is a little faster I guess? In the primitive days people used the EyeFi.

18m agoHN ↗

You would often not have wifi available, and you wouldn't want to have to type in wifi passwords to your camera all the time. But your phone will almost always be nearby and persistent bluetooth is easy.

2h agoHN ↗

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.

2h agoHN ↗

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.

1h agoHN ↗

I pretty much instantly wrote off physical media because I know I won't reliably move it to a separate location. If I'm going to have backups, I want ones that are not within fire/flood range of my computer.

In terms of preventing "oops" moments, I'm mainly relying on software (restic) for that, where I trust that (A) backups always append data rather than replacing and (B) it's logic works for marking which data to purge based on rules is accurate. [0]

[0] https://restic.readthedocs.io/en/stable/060_forget.html#remo...

1h agoHN ↗

I bought a tape library for my backups, but that's probably an overkill.

On the other hand, LTO-5 drives are now pretty affordable. And each tape cartridge holds around 2Tb of data for about $20.

35m agoHN ↗

Wait really ? That's a huge change from last time I looked. How much did this setup cost you?

47m agoHN ↗

Next best thing looks like the "object lock" feature on object store services that prevents deleting objects for a certain time.

Lol, no. "As of today we are closed. Goodbye."

Especially considering what giving even a two weeks now considered "generous".

3h agoHN ↗

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

2h agoHN ↗

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

2h agoHN ↗

Backups are boring. Restores, on the other hand, are often exciting.

2h agoHN ↗

Correct. In data protection, backup is not the feature. Restore is the feature.

44m agoHN ↗

https://en.wikipedia.org/wiki/Backup_Exec

No. But, well, yes: if you use BE - you will need a restore pretty soon.

I'm the person who actually experienced BE walking around the file server and deleting files. Helpful suuport person had done the needful and said what this is not an issue and it wouldn't be reported as a bug.

2h agoHN ↗

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).

1h agoHN ↗

How well did it work for restoring?

For me, the ability to mount a backup and look at a particular file proved to be important. Also, I restored from my backups four times; two of them was moving between machines, pretty quickly.

1h agoHN ↗

The problem with using glacier for backups is it's hard to run restore exercises, and without restore exercises, a backup is pretty dangerous

1h agoHN ↗

You can exercise it against regular, non-Glacier S3. Same flow; the only difference is that you skip one attribute on upload and one request/wait step on download.

2h agoHN ↗

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).

2h agoHN ↗

Yep, backup is a verb, restore is a noun. Testing restores is where the real work begins.

1h agoHN ↗

On my home PC I use restic, and (shockingly) I run it manually (via a script). I have a terminal banner that nags me when backup hasn't run in 24 hours, or displays spanish verb tables when it has (so I will notice if the banner doesn't show). I've been burned in the past losing a backup cron, and dead man's snitch seemed overkill for my needs here. And I've also forgotten what backup system was in place on a prior install, and it took me way longer than I liked figuring out how it was setup when I needed to do a restore.

Obviously for production systems automation & monitoring is the way. I kind of like this setup on my own machine though.

1h agoHN ↗

As an average-techie person, the only piece of data that i truly practice 3-2-1 is photos and videos. 1 on my phone, 1 on my small server running Immich, and 1 is on Google Photo(sadly, the quality is loss, but i can live with that).

Most of other data i only have 2 backup, usually 1 at my local machine(code) and 1 online(github). Yeah it's not ideal, but another question to ask yourself, is it truly worth it. I trust the engineers at MS doing much better job at backing up their data than me.

1h agoHN ↗

On the topic of backups, 7zip recently changed its handling of the FILE_ATTRIBUTE_ARCHIVE bit on unzipped files which caused an issue with some old software I was using. This is from the old DOS days with the BACKUP/RESTORE commands - the bit was set if any backup was made of the file. It's comically naive because it only assumes a single backup and this bit was forgotten to the sands of time until it was disturbed by some meddling kids!

31m agoHN ↗

So our first principle is to have a backup, i.e. a copy of your files someplace else. So far so good.

So who are we? A household with a localhost administrator?[0]

Then you are surely doesn't need encrypted, chunk-level corporate level bla-bla-bla.

You need a Syncthing copy to some other device not at home - and an additional backup procedure to maintain the history and protect against PEBKAC errors - which can run on your local Syncthing copy or/and the other one.

And no, nobody needs your 555GB of RAWs of sunsets/flowers/precious_family_moments you shot - not even you.[1]

[0] well considering the tone of TFA and most of the comments here

[1] that's Instagram/Google Photos/iCloud for nowadays, totally with "Remember this day N years ago?"

30m agoHN ↗

If you don't control your data size, it will end up controlling you and your backup choices, which will eventually lead to many avoidable, disastrous outcomes. Somehow, this gets missed in data storage and backup planning.

26m agoHN ↗

When it comes to software, it's almost never simple. What people think of as simple is rarely so.

For example:

Requirement:

"Just copy a file from folder A to folder B."

Minimal translation:

"Implement the capability to copy any file, in any format and of any size from SharePoint, located at a configurable path, with appropriate authentication and access control checks, then stream it in chunks to a different, configurable path inside an S3 bucket, also with appropriate authentication and access controls in place. Ensure that any disruption in either service which may occur while the file is streaming can be recovered from at the point it failed instead of having to restart from the beginning. Ensure that the retry mechanism is built-in and that the retry window is configurable; if the file cannot be copied within the specific time window, then an error should be sent via email to a configured email address. Ensure that the entire transfer is encrypted in transit... If the file happens to be a folder, then you must copy across all of its contents recursively up to a certain configured MAX_DEPTH to avoid DoS and ensuring that the system does not get caught in an infinite loop due to symlinks pointing to a parent folder... In this case, send an email to the configured address... Etc... Etc..."

And the thing is; if you tell AI "Just copy a file from folder A to folder B." - It will not meet your 'basic' needs because even if it does a great job at filling the gaps in your requirements, it will still take shortcuts. In order for an AI to avoid taking shortcuts, it would have to make you fill out a questionnaire and make you sign up for and configure services; it would not be a pleasant user experience. The user experience cannot be pleasant, because the AI cannot read your mind and it cannot know your intent.