> On 11/01/2021 05:18 Thomas Winterstein > <thomas.winterst...@rz.uni-augsburg.de> wrote: > > > we were able to narrow down the cause of the problem. > > > After the initial dsync migration process the mailbox GUIDs are the same > for each mailbox-name across all users. > Is this intended behaviour of dsync? > If not, how can this be changed? > > > After the first replication process the Inboxes of ~20% of users get > different mailbox GUIDs. > > > During the next incremental dsync process the mailbox GUIDs of these > ~20% get overridden by the inital one. > > > Then the incremental replication duplicates those Inboxes where the > mailbox GUIDs don't match. > > > Any ideas? > > > thanks > Thomas > > On 07.01.2021 16:41, Thomas Winterstein wrote: > >>> dsync is intended to be used to change mailbox format, so it should > >>> work just fine. > > > > that's exactly what we thought and why we use dsync to migrate like > > described here > > > > https://wiki2.dovecot.org/Migration/Dsync > > > > > > Our replication is configured according to > > > > https://wiki.dovecot.org/Replication > > > > > > Both processes run separately in time. > > > > > > Still on some accounts mails of Inbox or another folder get duplicated. > > We're currently trying to debug this. > > > > what are we missing? > > > > thanks > > Thomas > > > > On 07.01.2021 10:21, Aki Tuomi wrote: > >> dsync is intended to be used to change mailbox format, so it should > >> work just fine. > >> > >> Aki > >> > >>> On 07/01/2021 11:17 Andrea Gabellini > >>> <andrea.gabell...@telecomitalia.sm> wrote: > >>> > >>> Hello, > >>> > >>> I had a similar problem some time ago, and the problem was the mailbox > >>> format change. > >>> > >>> Please try to migrate with the same format. > >>> > >>> Andrea > >>> > >>> Il 05/01/21 15:02, Thomas Winterstein ha scritto: > >>>> No one? > >>>> > >>>> If there are limitations in regards to how dsync in migration and > >>>> replication can operate together these should be stated clearly in the > >>>> documentation. > >>>> > >>>> On 23.12.2020 20:33, Thomas Winterstein wrote: > >>>>> Hello everyone, > >>>>> > >>>>> > >>>>> we are working on migrating from dovecot 2.0.9 (maildir) to 2.2.36 > >>>>> (mdbox). The new cluster has two backend mail servers which replicate > >>>>> through doveadm replicator. To move the data initially we use doveadm > >>>>> backup (imapc). > >>>>> > >>>>> arb > >>>>> Our migration command > >>>>> doveadm -o mail_fsync=never backup -R -u $user imapc: > >>>>> > >>>>> > >>>>> To test the replication of new and purge of old mails with live data > >>>>> changes we ran imapc on a daily basis but encountered the problem > >>>>> that some mailboxes multiplied in size. We then made sure that imapc > >>>>> and replication don't run at the same time but after the first > >>>>> incremental imapc process, we still had the same problems. > >>>>> > >>>>> > >>>>> The doveadm-backup man-page states that it's possible to run it > >>>>> multiple times during migration. But is it also possible to have the > >>>>> replicator running in between? From our understanding the doveadm > >>>>> backup should just work as an imap connection between the servers, > >>>>> synchronizing all changes made on the source to the destination. Or > >>>>> does the conversion from maildir to mdbox format in our case produce > >>>>> the problems? > >>>>> > >>>>> > >>>>> If you're not supposed to run the replicator before having fully > >>>>> migrated, how can we shorten the downtime? rsync? And how can we be > >>>>> sure that similar problems don't occur after the migration if we > >>>>> can't test all mechanisms together with live data? > >>>>> > >>>>> > >>>>> thanks > >>>> > >>>> > >>>
When doing migration, it is very useful to construct a temporary dovecot-migration.conf which lacks *any* automatic mailbox creation and has only the bare minimum you need (sieve needs to be configured, and mailbox attributes). This means no autocreate/autosubscribe loaded, and no auto=create or auto=subscribe in namespace config. It is recommended not to have any mailbox Name entries in your namespace config. You should use doveadm -c /path/to/dovecot-migration.conf backup command on initial sync. The mailboxes must not exist before you do initial sync, if they do, you run into troubles. Aki
