On 04.12.2013 14:05, nux@li.nux.ro wrote:
On 04.12.2013 14:05, John Doe wrote:
>>>From: Listslists@benjamindsmith.com >>> > >>>>>>Our next big test is to try out ZFS filesystem send/receive in > >>>>>>lieu > >>>>>>of > >>>>>>our current backup processes based on rsync. Rsync is a fabulous > >>>>>>tool, > >>>>>>but is beginning to show performance/scalability issues dealing > >>>>>>with > >>>>>>the > >>>>>>many millions of files being backed up, and we're hoping that ZFS > >>>>>>filesystem replication solves this. >>> >>>Not sure if I already mentioned it but maybe have a look at: >>>?http://code.google.com/p/lsyncd/
I'm not so sure inotify works well with millions of files, not to mention it uses rsync. :D
-- Sent from the Delta quadrant using Borg technology! Nux!
I can attest to the usefulness of 'lsyncd' for large numbers of files (our file server has almost 2 million in active use, with a second backup server that's lsync'd to the first.
Things to note:
- Yes, lsyncd does use rsync, but it issues an 'exclude *' followed by
the list of only the file(s) that need updating at that moment.
- The inotify service can be jacked waaaay up (three kernel
parameters) to handle millions of files if you wish. Just make sure you have lots of RAM.
Be careful with it. Sadly I found out that inotify would consistently fail on InnoDB files (ibd); I had to use stupid while loops and check mtimes to perform some stuff that inotify-cron would've done much more elegantly ...
-- Sent from the Delta quadrant using Borg technology! Nux!
Interesting point, something I didn't know. Fortunately in my case there are no db files involved directly, just db dumps wrapped in a tarball along with other associated stuff, sent from other servers.
I would expect that lsync'ing db files could be a nasty non-stop process if the database is constantly being updated, so using db tools for replication would be best, configuring inotify/lsyncd to ignore the db directories. I believe by default that lsyncd instructs rsync to do whole-file transfers, so a large db could be a real problem.
Thanks for the important heads-up!
-
Chuck Munro