Error: Corrupted record in index cache file

[Aki Tuomi]

> On 05 December 2018 at 20:54 Orion Poplawski <orion at nwra.com> wrote:
> 
> 
> With dovecot-2.2.36-3.el7.x86_64 we had a couple hours where mail_plugins did
> not properly include zlib for all of the needed services.  This seems to have
> led to some corruption in our mdbox mailboxes.
> 
> I've run doveadm force-resync on a number of users, but I'm still seeing
> messages like this:
> 
> dovecot[13563]: imap(USER): Error: Corrupted record in index cache file
> /var/spool/imap/USER/mailboxes/INBOX/dbox-Mails/dovecot.index.cache: UID
> 67976: Broken physical size in mailbox INBOX:
> read(zlib(/var/spool/mail/USER/storage/m.1203)) failed: Cached message size
> smaller than expected (2978 < 8192, box=INBOX, UID=67976)
> 
> Is there anything that can be done about this?  Can I safely delete the
> dovecot.index.cache file?  I'm hesitant to do so since I understand that the
> mdbox format uses the index to store mailbox information and deleting at least
> some index files is a destructive operation.
> 
> Thanks!
> 
> -- 
> Orion Poplawski
> Manager of NWRA Technical Systems          720-772-5637
> NWRA, Boulder/CoRA Office             FAX: 303-415-9702
> 3380 Mitchell Lane                       orion at nwra.com
> Boulder, CO 80301                 https://www.nwra.com/

Erasing the cache file causes dovecot to recache the mails on access. It can cause performance issues, but no data loss.

Aki