[Dovecot] Zero-sized Maildir files and index corruption on over-quota

[Eric Shubert]

Edgar Fuß wrote:
> We are using Postfix as an MTA delivering via Dovecot's LDA (with sieve). We also use Dovecot as a POP/IMAP server. Mail storage is Maildir on NFS, indexes are stored locally. Quotas are FS quotas enforced by the NFS server. The Dovecot version is 1.2.11.
> 
> Recently, for one user being over quota, some attempts to deliver mail bounced as expected while some others resulted in zero-sized Maildir files. I can verify zero-sized files in cur, while I cannot tell whether they were already zero-sized in new. However, since nobody except Dovecot is accessing the mail storage, it's either Dovecot's LDA or Dovecot's IMAP producing the zero-sized files.
> 
> Logs show successful delivery (deliver: stored mail into mailbox 'INBOX') but ,,Corrupted index cache file /var/db/dovecot/indexes/XXX/.INBOX/dovecot.index.cache: Corrupted virtual size for uid=YYY: 0 != NNNN'' alerts on IMAP access.
> 
> It looks like all mails which correctly got bounced are >64KB while those resulting in zero-sized files are <64KB (there is one >32KB). My first guess would be that maybe for large files, write() fails, while for small ones, close() fails or there is some buffering involved for large files.
> 

Are your NFS Maildirs mounted on more than one server? Check the list 
archive for "nfs director". There has been a good bit of discussion 
about this recently. Cor Bosman explain the situation nicely here:
http://www.mail-archive.com/dovecot@dovecot.org/msg31713.html

-- 
-Eric 'shubes'