Doveadm backup...

Stephane Magnier steph.mag220 at netcourrier.com
Mon Feb 28 19:46:14 UTC 2022


I've seen in a previous post, that the fact to do an RSYNC might break 
the  index.. So, I've heard that this is not recommended. that's the 
reason why I decided to find a way to do a "clean" backup and be able to 
come back online if needed.

So, do you use an RSYNC and in case of restoring the mailbox, do you do 
a  simple

  *doveadm*  *index*  *-u*  *USERx*  *INBOX *And that's it ? works fine ?**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 for the 
mailboxes and a VM for the Email server and that could be another 
another point of failure :-*( *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..**

On 2/28/22 19:03, Ben Burk wrote:
>
> I'm not sure what you are attempting to do here. It looks like you 
> just ran a doveadm backup and the process completed for userx with a 
> warning that the remote system (your nfs mount) lost a particular 
> mailbox (possibly your indexes changed or a mailbox was deleted). From 
> the logs you pasted it appears the process completed normally.
>
> I personally do not use dovecot's backup or replication processes. If 
> I needed to I would use its replication process to sync active data 
> between multiple systems, but I have no need for this as of yet. 
> Personally I chose to create offsite backups using rsync a long time 
> ago, as rebuilding a mailbox (reindexing) is very simple.
>
> Try running            doveadm mailbox status -u userx guid '*'    as 
> the mailbox administrator and see if you can find that GUID, 
> 7e05c335174bf1608f0a02004eac7fb4. Also, see if the backup you've 
> written to nfs has the GUID.
>
>
> On 2/27/22 23:33, Stephane Magnier wrote:
>>
>> Well no ..I thought that dsync was for synchro " realtime for 2 
>> different places ?
>>
>> Having no 2 machines in parallel ( Just a single machine ) , I 
>> thought that a backup at regular interval  would be enough ?
>>
>> So, a simple backup should be done by dsync finally ?
>>
>> Do you recommend finally NOT to do a backup ( Doveadm backup ) but a 
>> replication process ? ( https://wiki.dovecot.org/Replication ) ?
>>
>> On 2/28/22 06:24, Ben Burk wrote:
>>>
>>> Did you try running dsync?
>>>
>>> On 2/27/22 23:15, Stephane Magnier wrote:
>>>>
>>>> HI,
>>>>
>>>> Any idea ? Any clue ?
>>>>
>>>> On 2/25/22 21:50, Stephane Magnier wrote:
>>>>>
>>>>> Hi
>>>>>
>>>>> I've recently tried to use the Dovecadm backup to backup the 
>>>>> emails..  with the following syntax
>>>>>
>>>>> doveadm -Dv backup -u userx maildir:/mnt/nfs-backup/userx
>>>>>
>>>>> Sounds to be OK with few emails... Some of them got a lot of 
>>>>> emails and one f them got an error and stop !
>>>>>
>>>>>     dsync(userx): Debug: brain S: Import Trash: Import change
>>>>>     type=expunge GUID=1725fa475d774ee19cb98dfb6737b4f1 UID=24891
>>>>>     hdr_hash= result=GUIDs match
>>>>>     dsync(userx): Debug: brain S: Import Trash: Import change
>>>>>     type=expunge GUID=916ed110b4b1522868be6194f1ae36ff UID=24892
>>>>>     hdr_hash= result=GUIDs match
>>>>>     dsync(userx): Debug: brain S: Import Trash: Import change
>>>>>     type=expunge GUID=eb8d75c530a7b02fc26b494d9006c91b UID=24893
>>>>>     hdr_hash= result=GUIDs match
>>>>>     dsync(userx): Debug: brain S: Import Trash: Import change
>>>>>     type=expunge GUID=aee9155875c34861fd6500f1f2f51a26 UID=24894
>>>>>     hdr_hash= result=GUIDs match
>>>>>     dsync(userx): Debug: brain S: Import Trash: Last common
>>>>>     UID=24894. Delayed expunges=
>>>>>     dsync(userx): Debug: brain S: Import Trash: Saved UIDs:
>>>>>     dsync(userx): Debug: brain S: Import Trash: Finish update:
>>>>>     min_next_uid=24895 min_first_recent_uid=24895
>>>>>     min_highest_modseq=35344 min_highest_pvt_modseq=0
>>>>>     dsync(userx): Debug:
>>>>>     /mnt/nfs-backup/userx/.Trash/dovecot.index.cache: Compressed,
>>>>>     file_seq changed 1645803588 -> 1645803589, size=32, max_uid=24894
>>>>>     dsync(userx): Warning: Mailbox changes caused a desync. You
>>>>>     may want to run dsync again: Remote lost mailbox GUID
>>>>>     7e05c335174bf1608f0a02004eac7fb4 (maybe it was just deleted?)
>>>>>     dsync(userx): Debug: auth-master: conn
>>>>>     unix:/run/dovecot/auth-userdb: Disconnected: Connection closed
>>>>>     (fd=10)
>>>>>
>>>>>
>>>>> I empty the trash... exactly the same problem...
>>>>>
>>>>> Any idea why this ??
>>>>>
>>>>> Thanks and regards,
>>>>>
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