UW IMAP 2GB file size limit

dunric · 11-15-2006, 05:41 PM

Until today imap server distributed in Slackware did served well but unfortunately I've suddenly encountered mbx file corruption. After a bit of searching I've finally discovered it's due to unhandled and undocumented >2GB file size limit. It's not a problem of used filesystem (ext3) but of uw-imap server itself.
Is there some fix or workaround about this serious limitation ? Besides of manual splitting, of course.

davidsrsb · 11-16-2006, 01:16 AM

Your mailbox is a single file, so this looks like a 32 bit limit
I use courier-imap, which uses maildir structure instead, so my limit will be the number of files in a folder directory imposed by the file system

dunric · 11-16-2006, 04:11 AM

Quote:

Originally Posted by davidsrsb

Your mailbox is a single file, so this looks like a 32 bit limit
I use courier-imap, which uses maildir structure instead, so my limit will be the number of files in a folder directory imposed by the file system

Yep, exactly. It's due to signed 32bit integer used for next message offset and file corruption is caused by its "overflow".
Unfortunately I didn't find a patch fixing this problem. I'm not sure I can hack the sources by myself so if I'd decide to switch to Courier is there some reliable tool for mbx -> maildir conversion ? Or at least mbox -> maildir ?

Alien Bob · 11-16-2006, 04:47 AM

I used imapsync to migrate IMAP mail from one IMAP server to another several times. The README file states that both UW-imap and Courier-imap are supported servers.

Eric

dunric · 11-16-2006, 05:40 AM

Thanks Eric. Imapsync looks handy.