Assistance with doveadm backup...
I am having trouble locating examples of how to use doveadm backup. All the examples I see are for sync. I simply want to create a backup to a network volume of the email server's vmail folders. The goal here is to have a reasonably current backup should the main drive on the email server go south.
We currently authenticate our users from a mysql database. User’s mailboxes are stored as domainname/username/Maildir
I assume what I will wind up on the network volume is a duplicate directory structure as the vmail folder on the email server?
Can someone help get me started here?
Jeff
On Feb 20, 2019, at 21:11, SH Development via dovecot <dovecot@dovecot.org> wrote:
Can someone help get me started here?
Does this help?
https://unix.stackexchange.com/questions/489331/what-is-the-correct-way-to-u...
-- This is my signature. There are many like it, but this one is mine.
Not really. The suggestions in the post seemed to be:
- Tar the whole directory, which I have tried in the past, but a 130G directory takes over 18 hours to tar.
- It was also suggested to rsync the directory, but the question was brought up, and not answered, about whether it was advisable to copy live mail, thus the need for doveadm sync/backup.
Based on what I’ve read about doveadm backup, this is what I need, I am just having a hard time formulating the syntax for the command.
Jeff
On Wed, 20 Feb 2019, SH Development wrote:
To: Joan Moreau via dovecot <dovecot@dovecot.org>
Jean did take over the list for a while when developing his FTS backend, so you can be forgiven that he actually runs this list.
You're right that consistency is a problem if you rsync a large amount of changing data. (If I remember correctly, mdbox is especially sensitive to content/index mismatches.)
One way this can be done is via filesystem magic i.e. filesystems with copy-on-write that allow you to take a moment in time snapshot of your entire filesystem e.g. LVM, ZFS and others. You can then rsync the snapshot, but some of these filesystem also support methods to export snapshots to a remote filesystem.
Joseph Tam <jtam.home@gmail.com>
On Thu, 21 Feb 2019 at 07:11, SH Development via dovecot < dovecot@dovecot.org> wrote:
In my previous life as a SysAdmin, I solved this kind of problem easily using the MTA. Exim is my MTA of choice and has a facility to do concurrent delivery to two storage locations using shadow_transport. I am guessing your MTA is Postfix (or maybe Sendmail). Try and see if they have such a capability or switch to Exim.
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Ok, so for lack of any other information, am I to conclude that the doveadm backup command is broken in 2.0.9? I have been through the wiki for it back and forth and cannot make it work.
Yes, I need to upgrade, there is no question, but I won’t do that without a maildir backup. I would prefer to use the built-in dovecot mechanisms for that than something else.
Jeff
Well for the purpose of upgrading your server, you could do the following:
- Rsync your maildir directories to a backup directory
- repeat rsync again so most of your changed files have been synced
- shut down your dovecot and smtp servers
- rsync one more time - should be relatively fast
- restart your dovecot and smtp servers
Otherwise, just schedule downtime and use whatever backup method you prefer. You will probably want to backup and then leave dovecot and smtp server down until you've completed the dovecot upgrade anyway, so you may as well schedule downtime for the entire process and do the dovecot upgrade between steps 4 and 5 above.
Natu
On 3/10/19 10:07 PM, Aki Tuomi via dovecot wrote:
participants (7)
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＠lbutlr
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Aki Tuomi
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Joseph Tam
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Natu
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Odhiambo Washington
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Sami Ketola
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SH Development