Strange index error on NFS after upgrade to CentOS 7 from 6

[Aki Tuomi]

> On 25/08/2020 16:43 Alessio Cecchi <alessio at skye.it> wrote:
> 
> 
> Hi,
>  
>  I'm running 3 Dovecot director and 6 Dovecot backend on CentOS 6 and Dovecot 2.3.10, with Maildir shared on NFSv3 (on NetApp).
>  
>  Since CentOS 6 will be EOL on November I started to upgrade to CentOS 7 the first Dovecot backend.
>  
>  But after Director start to direct users on new CentOS 7 server some errors, for any users, come up, an example:
>  
>  Aug 21 14:56:41 Error: imap(alessio at cecchi.it) session=<11sBlmKtj1qelGW/>: Mailbox INBOX: Broken or unexpectedly changed file /home/vmail/domains/cecchi.it/alessio/Maildir/dovecot-uidlist line 18664: Invalid data: - re-reading from beginning
>  Aug 21 14:56:41 Error: imap(alessio at cecchi.it) session=<11sBlmKtj1qelGW/>: Mailbox INBOX: Broken file /home/vmail/domains/cecchi.it/alessio/Maildir/dovecot-uidlist line 18664: Invalid data:
>  
>  Consequently to the error the user see the synchronization of his mailbox again.
>  
>  The Dovecot version and configuration is the same that in CentOS 6, also the mount parameters are the same, so I suspect that could be some difference in the NFS client implementation on CentOS 7.
>  
>  This the entry on fstab:
>  
>  192.168.1.2:/vmail0 /mnt/vmail0 nfs rw,nfsvers=3,noatime,nodiratime,_netdev,nordirplus 0 0
>  # Bind for vmail0
>  /mnt/vmail0/domains /home/vmail/domains none x-systemd.requires=/mnt/vmail0,x-systemd.automount,bind 0 0
>  
>  In the archive of this list I found a similar issue but without a solutions:
>  
>  https://dovecot.org/pipermail/dovecot/2018-October/113207.html
>  
>  Do you have any suggestions?
>  Thanks
> 
> -- 
> Alessio Cecchi
> Postmaster @ http://www.qboxmail.it
> https://www.linkedin.com/in/alessice

What versions are you running mixed?

Aki