Date: Wed, 03 Jul 2013 21:15:50 +1200 From: Berend de Boer <berend@pobox.com> To: Markus Gebert <markus.gebert@hostpoint.ch> Cc: freebsd-fs <freebsd-fs@freebsd.org> Subject: Re: EBS snapshot backups from a FreeBSD zfs file system: zpool freeze? Message-ID: <87zju43sxl.wl%berend@pobox.com> In-Reply-To: <14A2336A-969C-4A13-9EFA-C0C42A12039F@hostpoint.ch> References: <87li5o5tz2.wl%berend@pobox.com> <CA%2BtpaK1jQuKneQsxkVfxJGzXdPdLZfqBM1QWQ0e19nK5t71t1Q@mail.gmail.com> <87ehbg5raq.wl%berend@pobox.com> <20130703055047.GA54853@icarus.home.lan> <6488DECC-2455-4E92-B432-C39490D18484@dragondata.com> <CADBaqmihCB5JP01hLwXTWHoZiJJ5-jkT-Ro=oDwOcKZT_zvEKA@mail.gmail.com> <A5A66641-5EF9-454E-A767-009480EE404E@dragondata.com> <14A2336A-969C-4A13-9EFA-C0C42A12039F@hostpoint.ch>
next in thread | previous in thread | raw e-mail | index | archive | help
--pgp-sign-Multipart_Wed_Jul__3_21:15:49_2013-1
Content-Type: text/plain; charset=US-ASCII
>>>>> "Markus" == Markus Gebert <markus.gebert@hostpoint.ch> writes:
Markus> 1. snapshot the zfs at the same point in time you'd issue
Markus> that ioctl on Linux
Markus> 2. take the EBS snapshot at any time
Markus> 3. clone the EBS snapshot to the new/other VM
Markus> 4. zfs import the pool there
Markus> 5. zfs rollback the filesystem to
Markus> the snapshot taken in step 1 (or clone it and use that)
That seems like a very good first step!
It's unfortunately not automatic, but for recovery purposes it should
do.
Do you think (yes, I will definitely test this), that ZFS can mount a
file system consisting of a couple of disk (raidz2 setup), and access
it even though every disk might be a backup taken at a slighty
different time?
Obviously I'm going to throw away the mounted state and rollback to my
snapshot, but it has to be able to mount a set of disks which might be
in a terrible state first.
Markus> Also, taking the zfs snapshot should take much less time,
Markus> because you don't have to wait for the EBS snapshot to
Markus> complete before you can resume IO on the filesystem. So
Markus> you don't even depend on EBS snapshots being quick when
Markus> using the zfs approach, a big advantage in my opinion.
You don't have to wait for an EBS snapshot to complete. That can take
hours. EBS simply takes the moment in time you give the command, and
starts the backup from there. Normal I/O to the disk continues (so
uses some kind of COW system I suppose)
--
All the best,
Berend de Boer
------------------------------------------------------
Awesome Drupal hosting: https://www.xplainhosting.com/
--pgp-sign-Multipart_Wed_Jul__3_21:15:49_2013-1
Content-Type: application/pgp-signature
Content-Transfer-Encoding: 7bit
Content-Description: OpenPGP Digital Signature
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.17 (GNU/Linux)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=cXQg
-----END PGP SIGNATURE-----
--pgp-sign-Multipart_Wed_Jul__3_21:15:49_2013-1--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?87zju43sxl.wl%berend>