On 2023-02-01, Tim Evers <te-ml-...@artfiles.de> wrote: > I run a fairly large Dovecot Installation (around 100k mailboxes) on > several servers. > > gzip compression is on. > > Every once in a while I get the dreaded "cache corruption" messages in > the log: > > Error: Corrupted record in index cache file > /[redacted]/Maildir/dovecot.index.cache: UID 3868: Broken physical size > in mailbox INBOX: > read(zlib(/[redacted]/Maildir/cur/1674129792.M797543P21755.node2,S=8099,W=8276:2,)) > > failed: Cached message size smaller than expected (2877 < 8099, > box=INBOX, UID=3868) > > Error: Corrupted record in index cache file > /[redacted]/Maildir/dovecot.index.cache: UID 3875: Broken physical size > in mailbox INBOX: > read(zlib(/[redacted]/Maildir/cur/1674212201.M985809P29112.node2,S=13907,W=14121:2,)) > > failed: Cached message size smaller than expected (5533 < 8192, > box=INBOX, UID=3875) > > The first entry shows 2877 (size on disk) vs. 8099 (real size unzipped, > also in the filename: S=8099). > > The second entry shows 5533 (size on disk) vs. 8192 - this is not > correct in any way. Size on disk is 13907 as noted in the filename. > > Both mails were delivered trough LMTP and retrieved by the POP3 service. > > Anyone with an idea what might be happening here? I've read all > available info in the doc and in the previous discussions / bug reports, > but nothing seems to match my case. And where does that 8192 come from - > it looks suspicious? > > Version is 2.3.7.2 (Ubuntu 20.04)
2.3.7.2 is rather old now. There were definitely fixes regarding compression around the 2.3.10-2.3.12 timeframe or thereabouts (I forget all the details but it took a release or two before some remaining issues were sorted out after changes in the area). I'd be looking to get it updated to a current version first.