Yet another mail-restore question...

[Simon Matter]

Henrique de Moraes Holschuh schrieb:
> 
> On Tue, 07 Jan 2003, Simon Matter wrote:
> > I'm currently planning a new mailsystem so I'm interested in quick
> > recovery in case something goes wrong.
> 
> Quick recovery means you need to shutdown the mail system, LVM-snapshot the
> volume and restart it (if your system is well configured, this is quite
> fast, and can be done at 04:00 in the morning ;-)).
> 
> Then, copy the LVM snapshot somewhere safe, and unfreeze it.
> 
> There are other ways, of course, but you asked for the quickest recovery
> possible...
> 
> > My idea was the following:
> > - Using XFS or ext3 filesystem (XFS is the preferred one)
> > - Using LVM
> 
> You'll need both, unless XFS can snapshot by itself.  It is much faster than
> ext3, btw. I'm using it for postfix spools, and will try it in Cyrus spools
> one of these rainy days.

I have several servers, including Cyrus, running on XFS. It's really
cool to grow mounted filesystems on LVM while the server is running.

> 
> > - Having two servers. One real server and a 'snapshot' server.
> > The snapshot server is built with cheap, big IDE drives. Using rsync,
> > snapshots (well, sort of) are taken periodically and in the case of
> > failure, data can be restored quickly from this box.
> 
> That won't work quite perfectly, but it could work well.  The mail messages
> themselves are very rsyncable :-p  but if you want to make sure you won't
> lose state, you will need to have plaintext backups of the mailboxes db, and
> that the user is not using the mailbox when you copy it (due to the seen
> db).

I don't know a better solution without having to stop the server.

> 
> Still, it is what I would use myself, and there is a reason why the Cyrus
> debian packages take a silent plaintext snapshot of the mailbox db to the
> /var/backup directoriy every night by default :-P

I'll add something like that to the next cyrus rpm release.

Simon

> 
> --
>   "One disk to rule them all, One disk to find them. One disk to bring
>   them all and in the darkness grind them. In the Land of Redmond
>   where the shadows lie." -- The Silicon Valley Tarot
>   Henrique Holschuh

-- 
Simon Matter              Tel:  +41 61 695 57 35
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