Hello. Dovecot version: 2.2.36 OS: CentOS Linux release 7.9.2009 (Core) Kernel: 3.10.0-1160.11.1.el7.x86_64 I have two dovecot servers in replication master/master. Sometimes happens that deliver or imap process hangs and causing high CPU usage. In log's I only see locking failures but not initial cause why this happened. For mail storage I use ZFS pool with compression enabled. I made some digging and find this option: mmap_disable = yes. I will try this setting today evening. But I wondering if you have any idea why this happening and how to start solving this problems? Is there any additional setting like mmap_disable that can help solved this issues? -- BR -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://dovecot.org/pipermail/dovecot/attachments/20210622/ba95770c/attachment.html>