I hope I'm posting in the right place, hello, I'm a forum and linux newbie. I am a storage engineer and know enough proprietary linuxese to get by on my various arrays and FC switches. I have tried to find the answer to this question myself through Google but my linux ignorance stumps me. My question: is it possible with RedHat 6.6, filesystem ext3, clustered servers, to set up copy-on-write snapshots (not a clone) of a filesystem. I have no control over the filesystem version, it is ext3.

Thank you for any information and guidance!!

sandy

Probably not - read this page.
Good manual to download - as are the rest of those in the storage section (at least) - docs.redhat.com will get you started, just pick the right version.

If the reason why you are asking is because of compliance reasons, then I think that in itself will be argument enough to switch file systems.

I am no master at these things, but if versioning for audits are required, I think best to try moving to ext3cow.

Maybe setup a test box and try converting some of that system. If it goes smooth, you may be able to convince higher ups

Snaps of ext3 aren't the problem, clustering is the issue.
Using ext3 in a cluster in the first place might be a much bigger problem though.

Edit: I wouldn't be recommending a filesystem that hasn't had an update since 2008.

1 members found this post helpful.

Thanks much ericson & syg! I will look at the docs. I am migrating this data (~100TB) from an existing ext3 RedHat 6.6 server. We're keeping file system to ensure a good migration. It will be a one shot deal, I won't have the opportunity to backup the initial migration or remigrate if a follow-on filesystem upgrade runs into issues. Taking cluster out of the picture, that is an option.

I assume you know all this, but there are some considerations. Snaps are great for backup like that, but;
- snaps are "point in time". If that (source) filesytem is write active, you will lose any updates after the snap is taken.
- if it is (very) active, the snap will start consuming space - maybe (very) quickly. If the snap fills it will usually be automatically unmounted.