Imap processes apparentlt blocked on disk I/O
I have recently found a few blocked dovecot processes on a DragonFly 3.3 imap server.
Software: Dovecot-2.1.15, DragonFly-3.3 from March 11, 2013
ps auxw output:
user1 3361 0.0 0.0 31416 2804 ?? D1LM Fri03PM 0:01.42 imap: [user1 2001:7a8:1170:201:225:90ff:f
user1 3499 0.0 0.0 31484 2800 ?? D3LM Fri03PM 0:00.51 imap: [user1 2001:7a8:1170:201:225:90ff:f
PID USERNAME NICE SIZE RES STATE CPU TIME CTIME CPU COMMAND
3361 user1 0 31M 2804K clock 1 0:01 0:01 0.00% imap
3499 user1 0 31M 2800K clock 3 0:00 0:00 0.00% imap
The 'clock' state may be set from vfs_cache.c:356:
error = tsleep(&ncp->nc_locktd, PINTERLOCKED,
I have not found any other obvious place in sys/ using it.
The dovecot user stores emails on a Maildir directory on a HAMMER filesystem.
All files in the Maildir/ directory seem to be normally accessible; I could read it completely and store its
content into a tar archive without any issue.