[rescue] ZFS backup (was Re: Oracle making just...)

[Francois Dion]

On Mon, May 10, 2010 at 11:15 AM, Francois Dion <francois.dion at gmail.com> wrote:
> On Sat, May 8, 2010 at 7:16 AM, Rich Kulawiec <rsk at gsp.org> wrote:
>> On Fri, May 07, 2010 at 12:01:24PM -0400, Joshua Boyd wrote:
>>> What do you need from a zfsdump that zfs send won't do?
>>
>> Among other things, the ability to restore files on a system with
>> a different architecture and a different operating system.
>
> Different architecture, check. Different operating system, for that,
> you'll probably have to use star ( ftp://ftp.berlios.de/pub/star/ ).
> You can try, but if the version dont match, you'll get on the receive
> side:
>
> cannot mount 'simplex/livedata': Operation not supported
>
>
>> And perhaps this is just my lack of zfs savvy speaking, but it's
>> not clear to me yet how to do incremental backups using this method.
>> One of the systems that I run has ~40T of storage mostly consisting
>> of large files that are very infrequently modified (in some cases:
>> never) and I'd like to leverage that into making backups run as
>> quickly as possible and occupy as little space as possible.
>
> # zfs snapshot -r tank/home at 3am
> # zfs send tank/home at 3am > /backup/snaps/home.3am

Oh, and throwing the splitpipe in the mix to create a bunch of DVD sized chunks:

# zfs send tank/home at 3am | splitpipe -s dvd -o 'cat > home.3am.$SPVOLNUM'

SPVOLNUM is the env variable that increments each time the data going
thru the pipe reaches the size specified by -s.


> This does a full backup of your home zfs filesystem (recursive) on
> zpool tank. Instead of redirecting to a file like the above, you can
> also pipe to ssh zfs recv on a remote box. Of course, piping to a file
> doesn't guarantee data integrity because while zfs checksums the file
> i/os, the inflight data could get corrupted. The only way to do that
> is using the zfs send and receive pair (zfs recv will abort on error)

My above comment still applies, and I would restore using joinpipe and
zfs recv to make sure the backup is good before making a bunch of
DVDs...

Francois