Timo Sirainen tss@iki.fi wrote:
On 18.3.2012, at 0.28, Sven Hartge wrote:
mbox has big problems with concurrent writes, the bigger the mbox is, the more problems you get. This is mainly caused by the meta-data of a message (meaning flags, status, etc.) which is stored inside the mbox file itself. Flagging a message as read or replied causes the whole mbox file to be rewritten.
Dovecot moves only minimal amount of data within mbox. A flag change writes only a few bytes to mbox file, it doesn't rewrite it the whole file. Only time when the entire mbox file is rewritten is when you expunge the first message.
OK, then my memory was clouded by my exposure to the brokenness of uw-imapd and uw-popd, who rewrite an mbox file very often, resulting in abysmal performance.
Grüße, Sven.
-- Sigmentation fault. Core dumped.