On Tue, Dec 29, 2009 at 11:57:52PM +0200, Pasi Kärkkäinen wrote: > On Tue, Dec 29, 2009 at 10:50:52AM +0000, John Haxby wrote: > > 2009/12/28 Pasi Kärkkäinen <[1][email protected]> > > > > On Mon, Dec 28, 2009 at 03:51:59PM +0000, John Haxby wrote: > > > 2009/12/28 J Newbie <[1][2][email protected]> > > > > > > Btw, any other recommendation for backing up virtual machines. > > > > > [snip client-hosted backup] > > > > > > > We'd really need something like Windows VSS, to be able to coordinate > > the disk snapshots with the apps running in the guest.. > > > > That is possible and you don't need any especial software to do it. At > > least I didn't, not quite anyway. > > > > Yes, of course it can be done with custom scripts. > > I meant that it would be extremely good to have something similar as VSS > for Linux. Standard method to make safe/consistent backups. No need for > everyone to implement their own scripts :) > > > > I had a shell script that put the applications I was interested in into a > > "safe" state -- depending on the application this was either a suspend or > > just shutting it down (sendmail, for that one) -- did a sync and the > > reported back to the host that the guest was ready for a snapshot. When > > the snapshot had been taken the applications were either allowed to > > continue or restarted as necessary. > > > > This isn't perfect: the guest file systems are still marked dirty, but > > the > > sync ensures (I hope) that all the data is recoverable. > > > > Getting clean file systems would require a change to the kernel so that > > all disk activity is stopped and the various file systems are briefly > > marked clean while the snapshot is taken. I don't know if anyone, > > anywhere, is looking at that. > >
Linux 2.6.29 added generic filesystem freeze feature: http://lwn.net/Articles/287435/ http://kernelnewbies.org/Linux_2_6_29 So all the needed things are there. Someone just should make this simple library/API that can coordinate the snapshot/sync/flush/freeze process with the guest and the apps in the guest. -- Pasi _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
