[Dovecot] Any suggestions for backing up an imap server and whould maildir or dbox be better than mbox?
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 goetz.reinicke@filmakademie.de
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
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.
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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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] http://rsync.samba.org/tech_report/
Regards
- -- tomás
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tomas@tuxteam.de 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)
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 goetz.reinicke@filmakademie.de
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
participants (5)
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Eduardo M KALINOWSKI
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Eric T
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Eric Toczek
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Götz Reinicke
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tomas＠tuxteam.de