Doveadm backup...
Stephane Magnier
steph.mag220 at netcourrier.com
Mon Mar 28 05:10:48 UTC 2022
Hi John,
Thanks for sharing. Effectively, I prefer to check out and test it
before running into troubles.. and discovered that I have no backup up
and running :-)
1) OK thanks for the tips.. re-indexation..."doveadm index -u USERx INBOX"
2) Running : [root at mbox1 xenia]# doveadm mailbox status -u USERx guid '*'
Trash guid=f6e62d01c1847b6196f400004eac7fb4
Sent guid=a82520269daa79610a8a00004eac7fb4
Drafts guid=223789209daa79610a8a00004eac7fb4
Junk guid=2033a72b9caa7961038a00004eac7fb4
INBOX guid=2133a72b9caa7961038a00004eac7fb4
[root at mbox1 xenia]#
Sounds to be the mess ? :-) Different guid.. possibly
3) non, I din't try DSYNC.. to be honest I don't which way to go :-)
OK.I will see this :
doveadm -Dv backup -u userx maildir:/mnt/nfs-backup/userx
That might be the solution
with this syntax, I've seen the SSH version.. ? ( doveadm -Dv backup -u
userx ssh root at 1.1.1.1:/fold1/fold2 ) I don't know if this will work
In fact, I don't need a real time synchronization system. A simple
backup would be enough... but I wish to be able to retrieve a system
ASAP, which is down..
However, I am quite interested in knowing and studying a way to get a "
real time " synchronization system; where you have 2 emails servers in
parallel... but for now, a simple backup is enough
Thanks?? I will test some of your examples.
On 3/27/22 22:09, John Stoffel wrote:
>>>>>> "Stephane" == Stephane Magnier <steph.mag220 at netcourrier.com> writes:
> Sorry, I deleted your most recent email post before I could reply.
> But why don't you just do 'imapsync' instead from your production
> dovecot box to some other backup system? Otherwise I'd probably work
> to setup dovecot's own replication but only have it go one way.
>
> For example, I've got a VPS out in the cloud for my email, and I
> should probably back it up to my home system using replication, but it
> would be strictly primary->secondary. I wouldn't be trying to run two
> primaries replicating between each other.
>
> Imapsync would be an improvement over rsync because it works within
> dovecot, so you'd get a more consistent view, but maybe not quite as
> upto date. But how important is your email if you worry about losing
> 20 minutes worth of it? If it's that critical, then you should be
> investing in a more robust setup.
>
> John
>
>
> Stephane> I've seen in a previous post, that the fact to do an RSYNC
> Stephane> might break the index.. So, I've heard that this is not
> Stephane> recommended. that's the reason why I decided to find a way
> Stephane> to do a "clean" backup and be able to come back online if
> Stephane> needed.
>
> Stephane> So, do you use an RSYNC and in case of restoring the mailbox, do you do a simple
>
> Stephane> doveadm index -u USERx INBOX
>
> Stephane> And that's it ? works fine ?
>
> Stephane> 2) I will try the Backup , or Sync.. locally.. Effectively, I don't know where the problem comes from..I have effectively an NFS Mount
> Stephane> for the mailboxes and a VM for the Email server and that could be another another point of failure :-(
>
> Stephane> Thanks for sharing.. I am a bit in a rush... I realized that my backup maybe not correct.. and I prefer not to discover it while running into trouble..
>
> Stephane> On 2/28/22 19:03, Ben Burk wrote:
>
> Stephane> I'm not sure what you are attempting to do here. It looks like you just ran a doveadm backup
> Stephane> and the process completed for userx with a warning that the remote system (your nfs mount)
> Stephane> lost a particular mailbox (possibly your indexes changed or a mailbox was deleted). From the
> Stephane> logs you pasted it appears the process completed normally.
>
> Stephane> I personally do not use dovecot's backup or replication processes. If I needed to I would use
> Stephane> its replication process to sync active data between multiple systems, but I have no need for
> Stephane> this as of yet. Personally I chose to create offsite backups using rsync a long time ago, as
> Stephane> rebuilding a mailbox (reindexing) is very simple.
>
> Stephane> Try running doveadm mailbox status -u userx guid '*' as the mailbox
> Stephane> administrator and see if you can find that GUID, 7e05c335174bf1608f0a02004eac7fb4. Also, see
> Stephane> if the backup you've written to nfs has the GUID.
>
> Stephane> On 2/27/22 23:33, Stephane Magnier wrote:
>
> Stephane> Well no ..I thought that dsync was for synchro " realtime for 2 different places ?
>
> Stephane> Having no 2 machines in parallel ( Just a single machine ) , I thought that a backup at
> Stephane> regular interval would be enough ?
>
> Stephane> So, a simple backup should be done by dsync finally ?
>
> Stephane> Do you recommend finally NOT to do a backup ( Doveadm backup ) but a replication process ?
> Stephane> ( https://wiki.dovecot.org/Replication ) ?
>
> Stephane> On 2/28/22 06:24, Ben Burk wrote:
>
> Stephane> Did you try running dsync?
>
> Stephane> On 2/27/22 23:15, Stephane Magnier wrote:
>
> Stephane> HI,
>
> Stephane> Any idea ? Any clue ?
>
> Stephane> On 2/25/22 21:50, Stephane Magnier wrote:
>
> Stephane> Hi
>
> Stephane> I've recently tried to use the Dovecadm backup to backup the emails.. with
> Stephane> the following syntax
>
> Stephane> doveadm -Dv backup -u userx maildir:/mnt/nfs-backup/userx
>
> Stephane> Sounds to be OK with few emails... Some of them got a lot of emails and one f
> Stephane> them got an error and stop !
>
> Stephane> dsync(userx): Debug: brain S: Import Trash: Import change type=expunge
> Stephane> GUID=1725fa475d774ee19cb98dfb6737b4f1 UID=24891 hdr_hash= result=GUIDs
> Stephane> match
> Stephane> dsync(userx): Debug: brain S: Import Trash: Import change type=expunge
> Stephane> GUID=916ed110b4b1522868be6194f1ae36ff UID=24892 hdr_hash= result=GUIDs
> Stephane> match
> Stephane> dsync(userx): Debug: brain S: Import Trash: Import change type=expunge
> Stephane> GUID=eb8d75c530a7b02fc26b494d9006c91b UID=24893 hdr_hash= result=GUIDs
> Stephane> match
> Stephane> dsync(userx): Debug: brain S: Import Trash: Import change type=expunge
> Stephane> GUID=aee9155875c34861fd6500f1f2f51a26 UID=24894 hdr_hash= result=GUIDs
> Stephane> match
> Stephane> dsync(userx): Debug: brain S: Import Trash: Last common UID=24894. Delayed
> Stephane> expunges=
> Stephane> dsync(userx): Debug: brain S: Import Trash: Saved UIDs:
> Stephane> dsync(userx): Debug: brain S: Import Trash: Finish update: min_next_uid=
> Stephane> 24895 min_first_recent_uid=24895 min_highest_modseq=35344
> Stephane> min_highest_pvt_modseq=0
> Stephane> dsync(userx): Debug: /mnt/nfs-backup/userx/.Trash/dovecot.index.cache:
> Stephane> Compressed, file_seq changed 1645803588 -> 1645803589, size=32, max_uid=
> Stephane> 24894
> Stephane> dsync(userx): Warning: Mailbox changes caused a desync. You may want to
> Stephane> run dsync again: Remote lost mailbox GUID 7e05c335174bf1608f0a02004eac7fb4
> Stephane> (maybe it was just deleted?)
> Stephane> dsync(userx): Debug: auth-master: conn unix:/run/dovecot/auth-userdb:
> Stephane> Disconnected: Connection closed (fd=10)
>
> Stephane> I empty the trash... exactly the same problem...
>
> Stephane> Any idea why this ??
>
> Stephane> Thanks and regards,
>
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