On 5.3.2013, at 11.55, Evgeny Basov ya.mwork@yandex.ru wrote:
I tested dovecot's work with expunge messages on Mdbox over strace (see at tail of message). As I can see dovecot process opens old storage m.* file, reads it content, opens new temporary file, writes in this one content and rename this new one to m.(*+1).
You're talking about doveadm purge, right? Not expunge.
How fast this algorithm works on system with about 10000 users and 5Tb data? I will use mdbox_rotate_interval for delayed expunge but I think that simple delete file in Maildir must be faster than expunge from Mdbox.
Yes, Maildir/sdbox is faster when freeing up disk space for mails. Read and save operations should be faster in mdbox though. And if the purge is run at a time when there is less disk IO, it shouldn't be that bad.