Re: [Dovecot] Any suggestions for backing up an imap server and whould maildir or dbox be better than mbox?

[Götz Reinicke]

Hi,

Eduardo M KALINOWSKI schrieb:
> From: Götz Reinicke 
>> Hi,
>>
>> we run a Red Hat EL 5.2 mailserver with dovecot as the imap server. 
>> Mails are stored in mbox format and there are about 134GB of mail.
>>
>> At the moment users copy their importent mail to their workstation 
>> accounts wich are backed up nightly.
>>
>> What are your suggestions to back up the mails not copied? Thanks for 
>> any comments.
> 
> You can simply rsync the whole mail store. Gets pretty efficient after the 
> first run. Or take a look at rdiff-backup if you need to store previous 
> copies.


thanks for the idea! I'll try it. I've one more question: What will
happen to files which are locked or opend; e.g. if users are still
logged in?

> 
>> BTW: Dose changing the mailbox format from mbox to Maildir or dbox dose 
>> have any advantages?
> 
> I don't think it makes any difference in this case.

I thought about the filelocking, so if the mailbox is one big file
backing up things will be different from backing up a lot of smaler
files... But may be rsync dose handel this also in a different way?

Thanks once more

Regards

Götz
-- 
Götz Reinicke
IT-Koordinator

Tel. +49 7141 969 420
Fax  +49 7141 969 55 420
E-Mail [EMAIL PROTECTED]

Filmakademie Baden-Württemberg GmbH
Mathildenstr. 20
71638 Ludwigsburg
www.filmakademie.de

Eintragung Amtsgericht Stuttgart HRB 205016
Vorsitzende des Aufsichtsrats:
Prof. Dr. Claudia Hübner
Staatsrätin für Demographischen Wandel und für Senioren im Staatsministerium

Geschäftsführer:
Prof. Thomas Schadt

Re: [Dovecot] Any suggestions for backing up an imap server and whould maildir or dbox be better than mbox?

[Eric Toczek]

[EMAIL PROTECTED] wrote:
> Oh, no. Rsync is smarter than this. If you don't tell it _not_ to do it,
> it will transfer chunks of files which have changed and modify the
> target file in-place. How it does recognize what to do is actually worth
> a read [1].
>
> Note that this algorithm is ideal for files which are (mostly) appended
> to, like mboxes or log files.
>

Ah thanks, I hadn't looked too much into Rsync to see that it does
that.  Pretty slick.

So that being said reverse what I just said, Mbox is better for Rsync
then Maildir or Dbox (which would cause Rsync to run longer as it has
more files to look at to see if they've changed)

Re: [Dovecot] Any suggestions for backing up an imap server and whould maildir or dbox be better than mbox?

[tomas]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

On Thu, Oct 02, 2008 at 08:52:13PM -0400, Eric T wrote:
> 
> >> BTW: Dose changing the mailbox format from mbox to Maildir or dbox dose 
> >> have any advantages?
> > 
> > I don't think it makes any difference in this case.
> > 
> 
> It would make a difference if you were to Rsync. Since Rsync is done on
> a file level; with mbox every new message means that the entire mbox
> file will need to be copied out.

Oh, no. Rsync is smarter than this. If you don't tell it _not_ to do it,
it will transfer chunks of files which have changed and modify the
target file in-place. How it does recognize what to do is actually worth
a read [1].

Note that this algorithm is ideal for files which are (mostly) appended
to, like mboxes or log files.

[1] 

Regards
- -- tomás


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Re: [Dovecot] Any suggestions for backing up an imap server and whould maildir or dbox be better than mbox?

[Eric T]

>> BTW: Dose changing the mailbox format from mbox to Maildir or dbox dose 
>> have any advantages?
> 
> I don't think it makes any difference in this case.
> 

It would make a difference if you were to Rsync. Since Rsync is done on
a file level; with mbox every new message means that the entire mbox
file will need to be copied out. If you are using Maildir or dbox when
you run an rsync it will only copy over the new messages since last
Rsync run, being that it's a single new file per message.

Of course this holds true with any incremental type backups.



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Description: OpenPGP digital signature

Re: [Dovecot] Any suggestions for backing up an imap server and whould maildir or dbox be better than mbox?

[Eduardo M KALINOWSKI]

From: Götz Reinicke
> Hi,
>
> we run a Red Hat EL 5.2 mailserver with dovecot as the imap server.
> Mails are stored in mbox format and there are about 134GB of mail.
>
> At the moment users copy their importent mail to their workstation
> accounts wich are backed up nightly.
>
> What are your suggestions to back up the mails not copied? Thanks for
> any comments.

You can simply rsync the whole mail store. Gets pretty efficient after the 
first run. Or take a look at rdiff-backup if you need to store previous copies.

> BTW: Dose changing the mailbox format from mbox to Maildir or dbox dose
> have any advantages?

I don't think it makes any difference in this case.

[Dovecot] Any suggestions for backing up an imap server and whould maildir or dbox be better than mbox?

[Götz Reinicke]

Hi,

we run a Red Hat EL 5.2 mailserver with dovecot as the imap server. 
Mails are stored in mbox format and there are about 134GB of mail.


At the moment users copy their importent mail to their workstation 
accounts wich are backed up nightly.


What are your suggestions to back up the mails not copied? Thanks for 
any comments.


BTW: Dose changing the mailbox format from mbox to Maildir or dbox dose 
have any advantages?


Best regards

Götz Reinicke
--
Götz Reinicke
IT-Koordinator

Tel. +49 7141 969 420
Fax  +49 7141 969 55 420
E-Mail [EMAIL PROTECTED]

Filmakademie Baden-Württemberg GmbH
Mathildenstr. 20
71638 Ludwigsburg
www.filmakademie.de

Eintragung Amtsgericht Stuttgart HRB 205016
Vorsitzende des Aufsichtsrats:
Prof. Dr. Claudia Hübner
Staatsrätin für Demographischen Wandel und für Senioren im Staatsministerium

Geschäftsführer:
Prof. Thomas Schadt