I wanted to know the frequency at which different shops are backing up their repositories. I have heard some even go to the extent of every 5 minutes to prevent from having to worry about after a restore, going through everyone's local Projects to find and merge in any uncommitted changes that are missing after a restore.
Well, now that I think about it, there's really no reason that the repository couldn't be backed up more often, and automatically. And maybe it should.
I am using SVN on personal / consulting projects where I am the only developer.
I back it up at the end of every day of development to a flash drive.
At the office where we have 3-5 developers but DON'T USE SVN we are backing up the central repository once a night.
We're 3 developers and I'm doing a backup every night.
But that really depends of the server where you've your svn installed. Maybe it's doing shadow copies, it's a redundant server, .... That also depends of the amount of developers, how big is the project.
I don't think there's a single valid answer.
Most people adopt a fairly relaxed attitude to backups, with a "once in a blue moon policy".
Until that day.
You know the one.
After that day, you get pretty good at it. You figure you never want to lose more than a days work, and you make damned sure that's what happens! In answer the question, we perform a daily rsync of our subversion repository and trac database to an offsite location.
Same as other we backup at 4:30 everyday. However, there is one important point, never place your backup server in same room. Also move your backup DVD's to another location from time to time. In an event of catastrophe you will not loose everything.
When I managed the svnserver for a team of 15 or so developers:
1 developer. I back it up every night at 3am.
I use winzip to zip the entire repository and upload it to a remote ftp, so the backup I have is in a different physical location to prevent from data loss due to theft or fire.
I don't keep old backups since the svn repository itself contains all history.
I simply use winzip's internal scheduling for automatic zipping and ftp-uploading. Simple and effective
So don't forget to install the backed up copy once in a while onto a throwaway Subversion server, just to make sure that everything is fine.
I rarely backup my personal svn repository - I've been doing it manually about once a month since pre 1.4 days, and should really set up svnsync some time. svnsync is great. On the other hand, for a personal repository, a backup is slightly less crucial to me; I'd lose some history, but the important bits are in checkouts on several remote workstations which are themselves backed up; actual content wouldn't be lost.
At work, someone else manages the backup, and it's probably not a good thing that I don't have a clue as to the set up.
Seriously though, nowadays, with svnsync, a reasonable backup is trivial to set up. Sure, it won't include your commit hooks, and that's not good - but a trivial remote backup of all content is certainly a good thing. And as for commit hooks, you'll just need to back those up seperately. Since they're liable to change almost never, this is doable. With svnsync, you really can set the mirror to backup every 5 minutes - and best of all, the syncing mirror is itself a fully valid svn repository, which, if you plan it, can be used as a replacement svn server almost instantly should the primary server go down (you'd need to sort out things like access control, and replace svnsyncs hooks with your normal set, and you'd want to give the new server the same DNS name as the old server for a truly seemless transition).
Daily. Doesn't matter how many peoplle. Just run the backup as a cron job.
(At home I do a weekly backups)