Hi.

We use dovecot for replication on two dovecot nodes (using Maildir). Worked perfectly until upgrading from 2.3.13 to 2.3.17. I found out about it a couple of days after where Queued 'full resync' requests had gone up. ANd then i saw some failed requests. But nothing in the log. I found out which users having trouble and saw that it was new user so i ran doveadm sync manually and got the following error:

doveadm(2849817): Warning: Mailbox changes caused a desync. You may want to run dsync again: Remote lost mailbox GUID 38e69e0ba98d936142ac29004e3fea09 (maybe it was just deleted?)

So i found out that dovecot-uidlist had a mismatch on the Global Mailbox UID, so global mailbox uid is not the same on both servers. I don't know if there is something that has changed with regards to how this GUID is generated, because when i look at old mailboxes they are always identical on both servers.

I fix this issue manually by editing dovecot-uidlist on one of the servers making the global mailbox uid on both servers identical, and then run force-resync. This works, but i guess something has changed.

Dennis Højgaard
Powerhosting Support

t: +45 7222 4457 | e: dh@powerhosting.dk | w: https://powerhosting.dk