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

[Stefan Neben]

Sorry, i forgot to mention, that the storage format is mdbox and the
version is 2.2.27-3~bpo8+1 from jessie backports.

Kind regards
Stefan

2018-01-10 21:00 GMT+01:00 Stefan Neben <stefan.neben at gmail.com>:
> 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