I've been using dovecot for years, been working great. However recently I've come across two issues.
The first issue unfortunately I have little information on, mail_debug hasn't provided anything useful either (in fact it looks like the login request that fails doesn't even get logged at all).
During the morning rush of email, this server has around 11k mailboxes on it, it *appears* that one of the auth processes dies resulting in "dovecot: imap-login: Error: read(imap) failed: Connection reset by peer" errors followed by "dovecot: imap-login: Internal login failure ..." in the logs.
I've yet to get any useful debugging information on this error so I'm not expecting much/any help on this one, but if anyone has any ideas on how I can get more debug besides running strace 24/7 in the hopes it catches something before the hard drive is full of strace output I'd love to hear it.
The best I've gotten was a lucky strace once (at the time I didn't realize it was so lucky or I would have saved the output) that indicated the imap-login daemon was failing to connect to the auth process.
The second issue is lmtp/lda (tried both) delivery to a mailbox that has filesystem quotas enabled and the group quota is maxed is resulting in the below panic and crash.
This issue happens with 2.0.13, 2.0.15 and 2.0.16.
Here's the logs showing that it knows the disk quota is exceeded and then a subsequent zlib panic. Like it's trying to deliver it anyway.
11:21:07 [err] dovecot: lmtp(29691, admin@[redacted].com): Error: o_stream_send_istream(/email/d/r/[redacted]/[redacted]/admin/Maildir/tmp/1323458467.M245978P29691.fenrir.omnis.com) failed: Disk quota exceeded 11:21:07 [crit] dovecot: lmtp(29691, admin@[redacted].com): Panic: file ostream-zlib.c: line 144 (o_stream_zlib_send_flush): assertion failed: (zs->avail_in == 0) 11:21:07 [err] dovecot: lmtp(29691, admin@[redacted].com): Error: Raw backtrace: /usr/lib64/dovecot/libdovecot.so.0 [0x345443ca90] -> /usr/lib64/dovecot/libdovecot.so.0 [0x345443cae6] -> /usr/lib64/dovecot/libdovecot.so.0 [0x345443c4a3] -> /usr/lib64/dovecot/lib20_zlib_plugin.so [0x2ba2d31547f6] -> /usr/lib64/dovecot/lib20_zlib_plugin.so [0x2ba2d315481b] -> /usr/lib64/dovecot/libdovecot.so.0(o_stream_flush+0x2a) [0x345444f0ea] -> /usr/lib64/dovecot/libdovecot-storage.so.0(maildir_save_finish+0x6b) [0x3451c63b6b] -> /usr/lib64/dovecot/lib10_quota_plugin.so [0x2ba2d2f4ce7a] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mailbox_save_finish+0x30) [0x3451c2fbb0] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mail_storage_copy+0xb3) [0x3451c2aae3] -> /usr/lib64/dovecot/libdovecot-storage.so.0(maildir_copy+0x56) [0x3451c6fd36] -> /usr/lib64/dovecot/lib10_quota_plugin.so [0x2ba2d2f4d0ba] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mailbox_copy+0x5a) [0x3451c301ba] -> /usr/lib64/dovecot/li 11:21:07 [err] dovecot: master: Error: service(lmtp): child 29691 killed with signal 6 (core dumps disabled)
Attached is the current "doveadm config" output.
-- Brad Schuetz