On Wed, 2008-09-10 at 12:20 +0100, Mark Zealey wrote:
2008-09-10T11:56:07+01:00 mail8 dovecot: Panic: IMAP(xxx): Trying to allocate 2273345672 bytes 2008-09-10T11:56:07+01:00 mail8 dovecot: IMAP(xxx): Raw backtrace: /usr/libexec/dovecot/imap [0x80d0310] -> /usr/libexec/dovecot/imap [0x80d036a] -> /usr/libexec/dovecot/imap [0x80cfc2c] -> /usr/libexec/dovecot/imap [0x80d966c] -> /usr/libexec/dovecot/imap [0x80ce750] -> /usr/libexec/dovecot/imap(buffer_create_dynamic+0x30) [0x80ce800] -> /usr/libexec/dovecot/imap(mail_index_sync_ext_intro+0x4d5) [0x80c0145]
This should help: http://hg.dovecot.org/dovecot-1.1/rev/aa01f9077178
But as for why the transaction log file contained such a broken record in the first place:
About our setup: These are on an nfs-mounted file system. It's shared between two computers and connections are randomly redirected to either box; so potentially it could be an nfs type corruption issue. Timo, I'll send you a tarball of the dovecot* files off-list
Sounds like it could be because of NFS caching issues. You've set mail_nfs_index=yes, right? What OS? Linux should be OK, but FreeBSD has some issues.