On Tue, 16 Jul 2002, Andreas Dilger wrote:
> This is all done already for both LVM and EVMS snapshots. The filesystem
> (ext3, reiserfs, XFS, JFS) flushes the outstanding operations and is
> frozen, the snapshot is created, and the filesystem becomes active again.
> It takes a second or less. Then dump will guarantee 100% correct backups
> of the snapshot filesystem. You would have to do a backup on the snapshot
> to guarantee 100% correctness even with tar.
I think I'm missing a part of this, the "a snapshot is created" sounds a
lot like "here a miracle occurs." Where is this snapshot saved? And how do
you take it in one sec regardless of f/s size? Is this one of those
theoretical things which requires two mirrored copies of the f/s so you
will still have RAID-1 after you break one? Or are changes journaled
somewhere until the snapshot is transferred to external media? And how do
you force applications to stop with their files in a valid state?
-- bill davidsen <davidsen@tmr.com> CTO, TMR Associates, Inc Doing interesting things with little computers since 1979.- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Tue Jul 23 2002 - 22:00:26 EST