Hi again,
Here's some more information on the case.
In the meanwhile I tried the same setup with Dovecot 1.1.2, still the same result
As I saw in fstat on FreeBSD memory mapped files are ommited, so I did some further yet inaccurate monitoring with mmaped files included.
while [ : ]; do date; fstat -m -u dovecot |wc -l; sleep 1; done Wed Aug 6 18:37:05 CEST 2008 918 Wed Aug 6 18:37:06 CEST 2008 923 Wed Aug 6 18:37:07 CEST 2008 917 Wed Aug 6 18:37:08 CEST 2008 911 Wed Aug 6 18:37:09 CEST 2008 912 Wed Aug 6 18:37:10 CEST 2008 914 Wed Aug 6 18:37:11 CEST 2008 913 Wed Aug 6 18:37:13 CEST 2008 912 Wed Aug 6 18:37:14 CEST 2008 911 Wed Aug 6 18:37:15 CEST 2008 909 Wed Aug 6 18:37:16 CEST 2008 912 Wed Aug 6 18:37:17 CEST 2008 910
So actually I am very close to the 1024 FD barrier, so the question remains, if Dovecot inherits FD_SETSIZE from libc and if this might be the cause of the whole trouble.
During testing I did also a build of both 1.1.1 and 1.1.2 without SSL and mysql libraries, so basically just "plain" Dovecout without anything, though that made no difference at all.
Greetings,
Gianpaolo