[Dovecot] Bug when a duplicated file is found
Hello,
Last days we had to restore some mailboxes from backup. Our mailboxes are in maildir format and during restore, some duplicated files appeared. The situation is:
A user has messages in his new directory when the backup is made
In some moment after the backup is done, the user accesses to his mailbox, so the message is move to the cur directory.
We restore his mailbox directly to his maildir path, so the message is now at new directory too.
When this happens, dovecot detect it and it renames one of the files. This is the reported log:
Feb 13 23:08:05 myotis31 dovecot: imap(<user>): Warning: Fixed a duplicate: /home/alumnos/59/122559/Maildir/cur/1360169810.M670208P13643.myotis31,S=6282,W=6409:2, -> 1360793285.M721935P29136.myotis31
The problem with this is that we are using zlib plugin so messages are compressed. When the rename is done, the rename is to a name without the S=XXXX field (neither the W=XXX, although this field is less sensible), so the result is that user's can't access to any message after this one.
I think than in this situation, rename one of the files is a good solution (although it provokes duplicate mails, but this an expected/acceptable situation after the restore), but the rename should maintain the S= and W= fields (and even other maildir flags).
-- Angel L. Mateo Martínez Sección de Telemática Área de Tecnologías de la Información y las Comunicaciones Aplicadas (ATICA) http://www.um.es/atica Tfo: 868889150 Fax: 868888337
Am 25.02.2013 11:41, schrieb Angel L. Mateo:
Hello,
Last days we had to restore some mailboxes from backup. Ourmailboxes are in maildir format and during restore, some duplicated files appeared. The situation is:
A user has messages in his new directory when the backup is made
In some moment after the backup is done, the user accesses to his mailbox, so the message is move to the cur directory.
We restore his mailbox directly to his maildir path, so the message is now at new directory too.
When this happens, dovecot detect it and it renames one of the files. This is the reported log:
Feb 13 23:08:05 myotis31 dovecot: imap(<user>): Warning: Fixed a duplicate: /home/alumnos/59/122559/Maildir/cur/1360169810.M670208P13643.myotis31,S=6282,W=6409:2, -> 1360793285.M721935P29136.myotis31
The problem with this is that we are using zlib plugin so messagesare compressed. When the rename is done, the rename is to a name without the S=XXXX field (neither the W=XXX, although this field is less sensible), so the result is that user's can't access to any message after this one.
I think than in this situation, rename one of the files is a goodsolution (although it provokes duplicate mails, but this an expected/acceptable situation after the restore), but the rename should maintain the S= and W= fields (and even other maildir flags).
how you do the backup, dsync , rsync ??? perhaps you can avoid problems restore mail to another new named mailbox like restore.orig.name@somedomain.example, then the user himself or supporter, may copy restored mails himself to the orig mailbox or might be better in some subfolder i.e restore of the orig mailbox
Best Regards MfG Robert Schetterer
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El 25/02/13 11:53, Robert Schetterer escribió:
how you do the backup, dsync , rsync ???
With tivoliperhaps you can avoid problems restore mail to another new named mailbox like restore.orig.name@somedomain.example, then the user himself or supporter, may copy restored mails himself to the orig mailbox or might be better in some subfolder i.e restore of the orig mailbox
Yes, I know I can restore to another path and then import messages. The problem is that in a situation with no problem but duplicate mails, the user ends with a corrupted mailbox because dovecot rename a file to a wrong filename.
-- Angel L. Mateo Martínez Sección de Telemática Área de Tecnologías de la Información y las Comunicaciones Aplicadas (ATICA) http://www.um.es/atica Tfo: 868889150 Fax: 868888337
On 25.2.2013, at 12.41, Angel L. Mateo <amateo@um.es> wrote:
Feb 13 23:08:05 myotis31 dovecot: imap(<user>): Warning: Fixed a duplicate: /home/alumnos/59/122559/Maildir/cur/1360169810.M670208P13643.myotis31,S=6282,W=6409:2, -> 1360793285.M721935P29136.myotis31
The problem with this is that we are using zlib plugin so messages are compressed. When the rename is done, the rename is to a name without the S=XXXX field (neither the W=XXX, although this field is less sensible), so the result is that user's can't access to any message after this one.
I think than in this situation, rename one of the files is a good solution (although it provokes duplicate mails, but this an expected/acceptable situation after the restore), but the rename should maintain the S= and W= fields (and even other maildir flags).
participants (3)
-
Angel L. Mateo
-
Robert Schetterer
-
Timo Sirainen