Prompt to synchronize two volumes ZFS

[Artem Belevich]

On Mon, Apr 18, 2011 at 12:54 PM, Vladislav V. Prodan
<universite at ukr.net> wrote:
> 18.04.2011 21:12, Artem Belevich wrote:
>>
>> This page outlines ZFS replication process fairly well:
>> http://wikitech-static.wikimedia.org/articles/z/f/s/Zfs_replication.html
>
> I do not understand why dumps snapshot to a file and then deploy on a remote
> machine?
> You can not like something is poured snapshot to another server?
>
> zfs send -i export/upload at zrep-00001 export/upload at zrep-00002 | ssh
> otherservername "cat > /export/save/upload at zrep-00002"
> cat /export/save/upload at rzrepl-00002 | zfs recv export/upload
>
> Maybe there are some pitfalls?

They mentioned performance. mbuffer in-between receive and send makes
*a lot* of difference as long as you provide few seconds worth of
buffering at the rate your filesystems can sustain. I think the
authors of the page above just didn't use large enough buffer. You
would probably have to experiment yourself. In my case of ~3TB
transfer (mostly large files), I ended up with "mbuffer -m512M". I
also used mbuffer's built-in network transfer mechanism (see mbuffer's
-I/-O options) as at high data rates ssh became the bottleneck.

--Artem