On Sun, 14 Nov 2010 23:52:52 PST, sridhar surampudi <toyours_srid...@yahoo.co.in> wrote:
>Hi Darren, > >In shot I am looking a way to freeze and thaw for zfs file system so that for >harware snapshot, i can do >1. run zfs freeze >2. run hardware snapshot on devices belongs to the zpool where the given file >system is residing. >3. run zfs thaw The only thing I can think of that comes close is to make a recursive snapshot of the filesystems in the zpool, then run the hardware snapshot. The zfs snapshot will be zfs-transaction consistent. Your hardware snapshot wil contain the zfs snapshots in that same state. Even if you could quiesce zfs, there is no way to make sure the files are logically consistent, because applications can do whatever they like, application transactions don't have to synchronize with zfs transactions. There is no generic mechanism to force applications to flush their buffers/caches. For databases, a snapshot of the zfs on which database transactions are logged is important, but it will also contain unfinished database transactions. Your plan only more or less works in situations where all relevant applications can be quiesced/forced to write a consistent state, something like this: - quiesce the apps / databases - take the zfs snapshot(s) - thaw the apps - take the hardware snapshot -- ( Kees Nuyt ) c[_] _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
