Large number of snapshots on a ZFS system

Question

Here's my scenario: I have two servers (well many more, but two for this scenario), one is a Solaris backup server, the second is a CentOS Linux Server. Every night the CentOS server runs a cron job to rsync itself to the Solaris backup server. After this is done, it puts the date and time into a special file on the Solaris server. The Solaris server has a cron job run every minute and if it sees this file, it grabs the contents and uses that to make a snapshot.

The result is great: Every day the backup automatically runs and then creates a ZFS snapshot. Been working great for over two months. I had expected that by now I would be low on space and would need to start (manually) deleting old snapshots. But in fact, I am fine on space. My only concern is, with 60+ snapshots and more being added daily, are there any known problems with large numbers of ZFS snapshots? Is there a maximum number of ZFS snapshots a ZFS filesystem can have? Or am I OK to just keep accumulating snapshots until I am low on space?

Answer 1

There's no problem with lots of snapshots. Having thousands of ZFS filesystems can cause boot times of more than an hour, but you're not doing that.

Answer 2

I wouldn't be too concerned about this. You're talking about 1 snapshot a day here. I have heard of production environments with over 10k snapshots. But I don't have any information on how this was working for them but I didn't hear it in a bad context so I'm going to assume that it was working well.