"Digital data doesn't exist unless it's backed up in at least 3 locations".
I had a professor back in 2008 that hammered this into my brain and I share it every chance I get.
I lost my data trying to back it up
111–120 of 126 posts
Re: I lost my data trying to back it up
#112Earlier quoted context omitted.
This is how I treat it too. Always have a local backup, but an online or offsite one is also important. The mantra I've often heard repeated is "Two is one, and one is none".
Two is one; one is none is more of a military slogan. Backups should follow the 3-2-1 mantra, fullstop: 3 copies, on 2 different media, and 1 offsite.
I have heard so many different definitions for the 3-2-1 rule, I have no idea which is correct anymore.
It seems that you should have 3 copies -- 1 being offsite.
But the 2 I have heard the 2 as 2 formats, 2 devices, 2 mediums, 2 storage types, 2 technologies.
I don't think the idea of 2 is reasonable for anyone except the most hardcore. Am I really expected to buy a tape for my local personal backups?
I think this rule could be updated to something 2 different cloud providers. Or 2 different geographic regions. Drop the 3 and the 1.
Re: I lost my data trying to back it up
#113Earlier quoted context omitted.
Two is one; one is none is more of a military slogan. Backups should follow the 3-2-1 mantra, fullstop: 3 copies, on 2 different media, and 1 offsite.
I have heard so many different definitions for the 3-2-1 rule, I have no idea which is correct anymore. It seems that you should have 3 copies -- 1 being offsite. But the 2 I have heard the 2 as 2 formats, 2 devices, 2 mediums, 2 storage types, 2 technologies. I don't think the idea of 2 is reasonable for anyone except the most hardcore. Am I really expected to buy a tape for my local personal backups? I think this r…
If one of the copies is local and another is through an online backup, it's going to be a different in almost every way from local copies so you get the "2" by any definition.
If all your backups are to a set of tapes or, say 3 hard drives, and you have a rotation to keep one tape offsite, every copy shares too many traits in common. A fair number of Mac people use Time Machine to do versioned backups to an external drive (or drive array) and use separate software to simply mirror their drive to external drives, periodically swapping the onsite and offsite mirrored drives. To me, physically moving drives around is hardcore, I don't trust anything not automated, but it seems to be not that rare. I'm fairly lazy but my machine is a work laptop so I have a backup drive in the office, one at home, and have a cloud backup service so I have 3-2-1 without much thought or effort.
If backups are solely on hard drives, it's probably best to not use the same make/model purchased at the same time, for fear that they'll all fail within the same time frame.
Re: I lost my data trying to back it up
#114Earlier quoted context omitted.
It is very important to elaborate that a snapshot is not a backup of anything. If you snapshot a backup to provide a history of backups, then the resulting snapshot is also a backup (albeit not a new one, merely part of the original). However, if what you snapshot is not a backup, then neither is the snapshot. As a good rule of thumb: If you lose data when the machine suddenly bursts into flames in the most literal s…
GP's third sentence: > I keep 180 days with snapshots on the remote backup and 30 days for the local.
Yes? I am merely elaborating for clarity, as many have before drawn the conclusion that zfs snapshots are a backup tool on its own.
Re: I lost my data trying to back it up
#115Damn, this kind of screwing around with RAID is not what you do with your actual personal data. It’s like building your own car for your daily commute.
Re: I lost my data trying to back it up
#116Earlier quoted context omitted.
I agree with your idea, but your definition is overkill. A backup is a copy of data on hardware separate from the live system. A good backup is a backup in in a remote location. A backup strategy is to maintain a good backup. A good backup strategy is to have routine restore tests, to make sure that the backups serve their purpose. A great backup strategy requires at least 2 good backups.
I understand... by 3 full copies, that can include the active in-use copy. I just don't consider something backed up short of having the data in a separate device and location.
It has to be on a separate device to be a backup indeed, just like a spare wheel isn't a spare if you're driving on it.
The location thing is trickier, and while you can't have a any backup on the same device, you can have a bad backup on the same location. A bad backup is better than no backup by a long shot.
Re: I lost my data trying to back it up
#117I guess since I do devops sorts of things for a living where we treat servers as ephemeral, I don’t really even consider full drive backups any more.
Generally when I set up a computer, I use automatic configuration tools, and any sort of data store will have its own automatic backup and restore solution — or even better, won’t be on that server at all.
In the case of a home computer, I’ll install everything using ansible and homebrew (or the App Store or steam) and backup documents and photos to Dropbox and/or iCloud or s3, and all my code and dotfiles of course are on github.
I’ve spilled a soda on my laptop and been back up and running with a replacement in 10 or 15 minutes.
My whole house could burn down and in terms of data, I’d be at best mildly inconvenienced.
For people that don’t trust cloud, it’s way more likely that your physical copy is going to be lost or ruined than that multiple cloud services are going to lose your data.
Re: I lost my data trying to back it up
#118Getting backup right is extremely important, that is why you need proper tools. For the last 10 years I have been using ZFS snapshots and replication. I keep 180 days with snapshots on the remote backup and 30 days for the local. I use it to take backup of virtual machines, different databases including "running", sql servers. And of course important files, documents and photos. I've also configured a daily mail with…
What exactly do you do to verify that whatever you backed up was indeed backed up bit-for-bit and that the backup medium didn't just report success even though it didn't get some data stored correctly? Do you verify every backup using some tool? If yes, how long does that take? The reason I ask is because so many sites talk about the benefits of backing up regularly, using backup rotation and retention policies, etc.…
If you haven’t restored your data you aren’t doing backups.
At work once I set up data backups, the first thing I do is try and replace the backed up server with a restored server. And you should regularly do that if the data is at all important.
Re: I lost my data trying to back it up
#119Earlier quoted context omitted.
Two is one; one is none is more of a military slogan. Backups should follow the 3-2-1 mantra, fullstop: 3 copies, on 2 different media, and 1 offsite.
I have heard so many different definitions for the 3-2-1 rule, I have no idea which is correct anymore. It seems that you should have 3 copies -- 1 being offsite. But the 2 I have heard the 2 as 2 formats, 2 devices, 2 mediums, 2 storage types, 2 technologies. I don't think the idea of 2 is reasonable for anyone except the most hardcore. Am I really expected to buy a tape for my local personal backups? I think this r…
The idea behind '2' is to avoid having all your backups dependent on a single point of failure.
For example you religiously have three copies of data but they all came from the same tape drive that silently went bad months ago and has been writing garbage. Or you recieved a batch of bad tapes etc...
Re: I lost my data trying to back it up
#120Damn, this kind of screwing around with RAID is not what you do with your actual personal data. It’s like building your own car for your daily commute.
Yeah, when I first got into building PCs it was fun to do the most cutting edge, overclocked, using all possible features setups I could and then 3 years later have no memory of how things worked when I had to replace or fix something. Now I do absolute absolute bone stock simple idiot proof builds and get 90%+ of the performance.