zfs discuss - Mar 2010 - Moving Storage to opensolaris+zfs. What about backup?

Until now, I''ve ran Windows Storage server 2008, but the ... lack of
iSCSI performance has gotten me so fed up that I''ve now moved all the
files off the server, to install opensolaris with two zpools, and nfs+smb+iSCSI
sharing towards my windows clients, and vmware ESXi boxes (two of them). So far,
so good.

Among the smb data, there is also almost a terabyte of photography work, that I
_NEED_ backup of, which up until now has been performed using a HP 1/8G2 lto3
job (8 slots, 1 drive, LTO3 autoloader, 1u), connected by a sas-cable (connected
to an MPT)

However trying to wrap my head around solaris and backups (I''m used to
FreeBSD) is now leaving me with a nasty headache, and still no closer to a real
solution. I need something that on regular intervals pushes this zpool:

storage  4.06T  1.19T  2.87T    29%  1.00x  ONLINE  -

onto a series of tapes, and I really want a solution that allows me to have
something resembling a one-button-disaster recovery, either via a cd/dvd
bootdisc, or a bootusb image, or via writing a bootblock on the tapes.
Preferably a solution that manages to dump the entire zpool, including zfses and
volumes and whatnot. If I can dump the rpool along with it, all the better.
(basically something that allows me to shuffle a stack of tapes into the safe,
maybe along with a bootdevice, with the effect of making me sleep easy knowing
that ... when disaster happens, I can use a similar-or-better specced box to
restore the entire server to bring everything back on line).

are there ... ANY good ideas out there for such a solution?
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This message posted from opensolaris.org

Comments inline :
 
On Wednesday, March 03, 2010, at 06:35PM, "Svein Skogen" <svein at
stillbilde.net> wrote:
>
>However trying to wrap my head around solaris and backups (I''m used
to FreeBSD) is now leaving me with a nasty headache, and still no closer to a
real solution. I need something that on regular intervals pushes this zpool:
>
>storage  4.06T  1.19T  2.87T    29%  1.00x  ONLINE  -
>
>onto a series of tapes, and I really want a solution that allows me to have
something resembling a one-button-disaster recovery, either via a cd/dvd
bootdisc, or a bootusb image, or via writing a bootblock on the tapes.
Preferably a solution that manages to dump the entire zpool, including zfses and
volumes and whatnot. If I can dump the rpool along with it, all the better.
(basically something that allows me to shuffle a stack of tapes into the safe,
maybe along with a bootdevice, with the effect of making me sleep easy knowing
that ... when disaster happens, I can use a similar-or-better specced box to
restore the entire server to bring everything back on line).
>
>are there ... ANY good ideas out there for such a solution?
>-- 
Only limited by your creativity.  Out curiosity, why the tape solution for
disaster recovery?  That strikes me as being more work, not to mention much more
complicated for disaster recovery since LTOs aren''t usually found as
standard kit on most machines.  As a quick idea how about the following :

Boot your system from a USB key (or portable HD), and dd the key to a spare
that''s kept in the safe, updated when you do anything substantial. 
There you recover not just a bootable system but any system based customization
you''ve done. This does require downtime however for the duplication.

For the data, rather than fight with tapes, I''d go buy a dual-bay disk
enclosure and pop in 2 2Tb drives.  Attach that to the server (USB/eSATA,
whatever''s convenient) and use zfs send/recv to copy over snapshots
into a full exploitable copy.  Put that in the safe with the USB key and you
have a completely mobile solution that wants only a computer. Assuming that you
don''t fill up your current 4Tb of storage, you can keep a number of
snapshots to replace the iterative copies done to tape in the old fashioned
world. Better yet, do this to two destinations and rotate one off-site.

That would be the best as far as disaster recovery convenience goes, but does
still require the legwork of attaching the backup disks, running the send/recv,
exporting the pool and putting it back in the safe. Using a second machine
somewhere and sending it across the network is more easily scalable (but more
possibly expensive).

Remembering that by copying to another zpool you have a fully exploitable backup
copy.  I don''t think that the idea of copying zfs send streams to tape
is a reasonable approach to backups - way to many failure points and
dependencies. Not to mention that testing your backup is easy - just import the
pool and scrub.  Testing against tape adds wear and tear to the tapes and you
need room to restore to, is time consuming, and a general PITA. (but
it''s essential!)

If you want to stick with a traditional approach, amanda is a good choice, and
OpenSolaris does include an ndmp service, although I haven''t looked at
it yet.

This kind of design depends on your RTO, RPO, administrative constraints, data
retention requirements, budget and your definition of a disaster...

IMHO, disk to disk with zfs send/recv offers a very flexible and practical
solution to many backup and restore needs. Your storage media can be wildly
different - small, fast SAS for production going to fewer big SATA drives with
asymmetric snapshot retention policies- keep a week in production and as many as
you want on the bigger backup drives. Then file level dumps to tape from the
backup volumes for archival purposes that can be restored onto any filesystem.

Cheers,

Erik

The problem is that all disks I''ve seen so far, has been more fragile
than tapes (given a real disaster, such as a clumsy sysadmin, or a burning home
falling on top of them)... Trust me to knock over a disk.

//Svein
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