Error: Corrupted index cache file

[Aki Tuomi]

> On 10/02/2023 17:15 EET Sohin Vyacheslav <slawa at vivaldi.net> wrote:
> 
>  
> Hi All,
> 
> In mail.log exists an error messages "Error: Corrupted index cache file 
> /data/mail/vhosts/domain.com/user at domain.com/Maildir/dovecot.index.cache: 
> invalid record size" for some accounts.
> 
> I tried these steps to fix it:
> 
> 1. Running commands
> # doveadm -D -v index -u user at domain.com INBOX
> # doveadm -v force-resync -u user at domain.com INBOX
> 
> after this I saw that the following files are updated in ../Maildir/:
> dovecot.index.cache
> dovecot.index.log
> dovecot-uidlist
> 
> But after some time error messages occurred again.
> 
> 2. Added NFS mount option 'nordirplus' to /etc/fstab with remount /data 
> partition, add 'mmap_disable = yes' and 'mail_fsync = always' to 
> 10-mail.conf as advised on 
> https://doc.dovecot.org/configuration_manual/nfs/ (because /data 
> partition mounted via NFS);
> 
> 3. Renaming 3 files with/without Dovecot service pre-stop.
> 
> # mv dovecot.index old.dovecot.index
> # mv dovecot.index.cache old.dovecot.index.cache
> # mv dovecot.index.log old.dovecot.index.log
> 
> Unfortunately, all done steps didn't fix issue.
> What is the proper way to fix corrupted index cache errors?
> 
> 
> dovecot package: 1:2.2.33.2-1ubuntu4.8 (Ubuntu-18.04).
> 
> 
> p.s. for some of email accounts also exists error messages "Error: 
> Broken file ../Maildir/dovecot-uidlist line ###: Invalid data:" besides 
> mentioned cache error.
> 
> 
> -- 
> Best wishes
> Sohin Vyacheslav

It sounds like your NFS is somehow managing to break the files, this can happen easily if same user is accessed by two backends concurrently.

Aki