Hi All, I upgrade my mail server from doveot 1.1.7 to 2.2.13 and encounter problems with file locking issues. The server has around 400 clients using IMAP and I get tons of "Warning: fscking index file .. dovecot.index" and "Error: Corrupted transaction log". Sometimes the transaction log problem is followed by "Panic: file mail-transaction-log.c: line 350 (mail_transaction_log_set_mailbox_sync_pos): assertion failed: (file_offset >= log->head->saved_tail_offset)" I tried all offered locking methods (fcntl, flock, dotlock) without success. The server runs inside a virtual guest (linux-vserver which is similar to LXC) using an overlay filesystem. I suspect the overlayfs but have no idea how to test this, besides - as I understand - dotlock should not rely on the fs locking at all :( I even wonder why the old dovecot worked for nearly 10 years without any problems, even under higher loads. The config is pretty straightforward: # 2.2.13: /etc/dovecot/dovecot.conf # OS: Linux 3.4.57-vs2.3.3.9-g67e6589-dirty x86_64 Gentoo Base System release 2.2 auth_cache_negative_ttl = 0 auth_cache_size = 50 M auth_mechanisms = plain cram-md5 debug_log_path = /var/log/dovecot-debug.log default_client_limit = 900 default_process_limit = 250 disable_plaintext_auth = no first_valid_gid = 89 first_valid_uid = 89 info_log_path = /var/log/dovecot.log last_valid_gid = 89 last_valid_uid = 89 listen = * lock_method = dotlock login_greeting = Serverpilot.net Mail Service mail_gid = 89 mail_location = maildir:~/.maildir mail_uid = 89 namespace inbox { inbox = yes location mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix } passdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } protocols = imap pop3 service imap-login { process_min_avail = 5 service_count = 0 } ssl_cert = </var/qmail/control/servercert.pem ssl_cipher_list = ALL:!EXPORT:!LOW:!MEDIUM:!aNULL:+RC4:@STRENGTH ssl_dh_parameters_length = 2048 ssl_key = </var/qmail/control/servercert.pem ssl_protocols = !SSLv2 !TLSv1.2 userdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } protocol imap { mail_max_userip_connections = 25 } Any ideas are welcome. Oliver -- Protect your environment - close windows and adopt a penguin! -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 4074 bytes Desc: S/MIME Cryptographic Signature URL: <http://dovecot.org/pipermail/dovecot/attachments/20150116/c8b75760/attachment.p7s>