Panic: file mail-index-util.c: line 37 (mail_index_uint32_to_offset): assertion failed: (offset < 0x40000000)

[Stefan Neben]

Hello,

i have a problem with a very huge mail account.

The INBOX of this account has ~1.1 - ~1.7 million mails inside. And
from time to time the index cache make problems and i got the
following in the logs:

--- Snip ---
Jan 10 20:43:04 XXXXX dovecot: imap(XXXXX): Panic: file
mail-index-util.c: line 37 (mail_index_uint32_to_offset): assertion
failed: (offset < 0x40000000)
--- Snap ---

I skip the raw backtrace to keep the post "small", but can hand it in
later if needed. Got this for UID FETCH, UID SEARCH, UID SORT, ...

The size of the file dovecot.index.cache of INBOX was in the last seen
problem situations between 1.1GB to 2.3GB.

To solve the problem the last times was to reduce the amount of mails
to under 1.7 million (seems to be the limit to trigger the problem),
delete the index cache and let him rebuild with a controled request.
But this is a odd situation (because it confused 3rd party tooling,
which access this mailbox) and i cannot find any helpful informations
to solve this problem.

Sharding it into several folders to keep the amount of mails in INBOX
small is not an option currently.

If further informations are needed, just let me know. Thanks for any help!


Kind regards
Stefan