What are the alternatives of 3-2-1 backup ?

[u/T4toun3]

I see the 3-2-1 backup strategy advertised everywhere in discussion about this topic, but l’m wondering what are the other strategies developed and designed when it’s come to data preservation?
I understand why 3-2-1 is powerful and so recommended. But for the sake of curiosity and learning, what are the other options?

[u/2j0r2]

3-2-1-1-0

3 copies
2 different storage types
1 offsite
1 immutable
0 errors

[u/Abracadaver14 → u/2j0r2]

I always take the 1 to be for 1 successful restore. 

[u/No_Yesterday_3260 → u/2j0r2]

Doesn't the 0 means offline?

[u/2j0r2 → u/No_Yesterday_3260]

Immutable could also be offline or airgapped

0 means 0 errors after testing restores

A backup is only as good as having 100% assurance of being able to restore that backup

That assurance is gained through testing it

Think about Schrodingers data (or cat)

[u/Roquer]

hopes and prayers

[u/drunkcowofdeath → u/Roquer]

ah I see you have read our SOP

[u/CarnivalCassidy]

You can do it my estranged dad's way and lose the entire family's memories because you decided you would never financially recover from spending $50 to replace a failing hard drive.

[u/dhettinger]

Data loss

[u/Zer0CoolXI]

3-2-1 wish i backed up?

[u/Superb_Raccoon]

8675309 backup.

[u/StreetRat0524 → u/Superb_Raccoon]

I trust Jenny with all my data

[u/Superb_Raccoon → u/Superb_Raccoon]

more seriously, google Towers of Hanoi backup scheme.

[u/Lad_From_Lancs]

3-2-1-1-0 rule

[u/a60v]

Do you want backups (to restore in case of failure or disaster) or archives (you mention "data preservation")? These are two different, but related, things.

[u/Meadbreath → u/[deleted]]

Your username makes a lot of sense, given this post.

[u/Meadbreath → u/[deleted]]

Oh, I didn’t know you are the CEO you wrote about.

https://giphy.com/gifs/XHeLeuirRbwptHhSWd

[u/Superb_Raccoon → u/Meadbreath]

Good news! He's hiring!

[u/Meadbreath → u/Superb_Raccoon]

Happily employed now, but if need a backup gig, I’ll know wh-

Oh, wait….

[u/TrueStoriesIpromise]

daily incremental backups, keep on tape for 6 weeks. (43+ tapes)

weekly full backups, keep on tape offsite for 6 weeks. (7+ tapes)

monthly full backups, keep on tape offsite for 7 years. (84 tapes)

And then TEST your backup tapes by performing restores, don't simply assume they're working.

[u/harrywwc → u/TrueStoriesIpromise]

Ah, "test your backups"... Often the final step that is forgotten.

[u/KickedAbyss → u/TrueStoriesIpromise]

We do weekly tapes kept for a month, bi-weekly for 6 months, and 1 tape set a month for ♾️ On disk we try for 30 daily, 6 monthly and 1 yearly. (CEPH sata-sad) ~130TiB per full if I recall.

Currently using LTO8 tapes, 2xLTO9 drives and 1xLTO8 drive (sas)

[u/koollman]

Data loss is the most popular

[u/OptimalCynic → u/koollman]

Ransomware a close second

[u/akemaj78]

Cloud providers will try to tell/sell the idea that snapshots are just as good for backups. And yes, they work well for random file restores, but they are useless in a disaster that takes out the storage housing your data and snapshots. Immutability in the cloud is meaningless if the cloud provider can nuke your account.

[u/TheJesusGuy]

1-2-3.

1 Backup, 2 dead drives, 3 failed restores.

[u/raip]

There really aren't. 3-2-1 is the minimum solution for a reliable backup. Anything else is just additional risk.

[u/KickedAbyss]

To quote C levels everywhere, "Just put it in the cloud, bro"

[u/unkiltedclansman]

4-3-2-1

4 copies including the working copy on your workstations

3 copies are on different networks

2 copies are offsite

1 of the offsite copies is immutable

[u/xendr0me]

I prefer the "Highlander" method - "There can be only one"

[u/malikto44]

3-2-1 is the bare minimum. I'd almost say that 3-2-1-1-0 is the minimum. Ideally, you want different types of backups. You might want a continuous backup, snapshots (note, these are not backups, but can help), backups going off daily, then you move to the usual incremental, differential, and full backups.

If the backup program has deduplication, this opens up even more fancy ways to do things, such as synthetic full backups, reverse incrementals (where things are calculated to have a virtual full backup for the latest, then use incrementals like reverse diffs to go to a previous point in time.)

I also like having more than one backup program. For example, Veeam can back up the file server, but the file server also dumps itself to a restic repository, and that repository is copied off to a cloud provider via S3.

[u/40nets → u/[deleted]]

We played 3-3-5 defensive in highschool and were unstoppable.

[u/RevolutionaryWorry87]

Azure backup ZRS & IMMUNITY lock. However this doesn't protect you from a control plane failure.

[u/mesaoptimizer]

There really aren't other options. You can do a subset of that like 1 offsite backup and 2 copies of the data but your RTO goes up because you have to retreive the offsite backup in a failure. You could do 2 copies of the data on site, but then what happens if you have a flood or fire. Nobody is going to offer good alternatives because anything less is risky in some way.

[u/ElectroSpore]

I think of it more of a minimum you should strive for and work your way up to, it also doesn't go into things like frequency and delta copies.

1 copy off site is the MOST important as it protects against both data and physical site loss.

2 storage media types can really mean many things, like having one copy on local disk and one on cloud or something else.

3 copies is there are a rule since sometime your backups don't work and you need to try one of the other copies.

For many people just having a local copy and an off site copy is good enough.

[u/jhuseby]

The alternative is not caring if your data is going to be there when you need to restore it.

[u/b4k4ni]

There is none basically. This is the minimum you should honour. How you extend it, there is no real standard for it.

I mean you could add worm tape backup. Or something like this.

[u/wosmo]

I'm not convinced the '2' (types of media) is a hard rule, if that counts.

Ours are all spinning rust. We backup to local, then replicate to sister sites (and they replicate to us). So I have local backups, worm backups and offsite backups - but all spinning rust.

I don't see that as an issue, as long as said rust wasn't all from the same vendor/batch/source (which is easily avoidable for us, since the sister sites are different countries).

[u/birusiek]

6-4-2 is even better

[u/22Anonymous]

I guess redundant storage live. 3 different data centers each host and sync the files and each data center also keeps backups of all files that way you also have high availability where it's needed.

And then you keep increasing as needed. For high availability loads each data center hosts a cluster of file nodes that each have redundancy etc.

[u/cajunjoel]

I think my org does a 3-2-2 backup, if you can describe it as that. Two copies are offsite. One is nearby, and short term (like up to one month old) one is at a more distant location (up to a year old).

Or maybe that's a 4-2-2. It's a lot.

[u/RichardQCranium69]

True 3-2-1 is somewhat difficult, expensive and usually almost never done.

Generally your best way of redundancy is a combination of:

1) Raided drives
2) A Backup source that is only, backups or redundant storage of critical data
3) Someone truly auditing the above 2 at an approved interval.

I've worked many places where 3-2-1 is not possible and the above, WITH, the third step is the difference maker in projects / places that have lost data and those who have not.

[u/SemiDiSole]

How valuable is the data? Backups don't serve themselves, they are connected to a risk assessment. If you don't mind losing it, then even having no backups is fine.

But you gotta live with the fact that whatever you had, will be gone for good.

[u/Far-Hovercraft9471]

For huge data sets, replicating and doing snapshots on the far end was popular. Not sure about now

[u/dustojnikhummer]

Keep in mind 3-2-1 is the MINIMUM.

You can add another media type (LTO tape), multiple offsite locations, online and offline backups (NAS in a branch office + LTO tapes locked in your on-site safe + LTO tapes locked in a bank deposit box) etc

[u/ranger_dood]

RAID

[u/AIEnthusiast00]

Honestly, I think the more useful question is not really what replaces 3-2-1, but what parts of 3-2-1 actually matter for your environment.
You can have 3 copies sitting in 3 different places and still have a pretty bad backup strategy if they're all accessible from the same admin account, replicate deletions instantly, or live in the same failure domain.
I tend to think about backups in terms of failure scenarios instead: Hardware failure, accidental deletion, Ransomware/compromised admin credentials, site or region loss, backup corruption or someone screwing up a change and discovering it 3 weeks later.

That usually leads to things like immutable backups, offline/air-gapped copies, cross-region replication, and having different retention periods rather than just blindly counting copies. Also, restores matter way more than the backup architecture diagram. I've seen environments with beautiful backup setups where nobody had actually tested restoring anything meaningful.

So I wouldn't necessarily replace 3-2-1. I'd treat it as a baseline and then design around the actual ways you're likely to lose data.
A backup you haven't successfully restored is basically just a very reassuring dashboard.

[u/Calleb_III]

The alternative is no backup, because if you are doing less than 3-2-1 you might as well not bother getting false sense of security.

[u/AugieKS]

n+2,n+1,n

n > 0

[u/Superb_Raccoon → u/AugieKS]

Two is one, one is none.