Daemon Tools

daemontools

A collection of programs written by DJB.

Most this page is about using the svc and svstat commands in working with qmail. The same ideas can be applied to djbdns as well (dnscache for instance).

See also

• http://cr.yp.to/daemontools.html
• http://www.hackinglinuxexposed.com/articles/20020716.html

It is typical for qmail to run under the supervise command. If so, these commands will tell supervise that qmail should be stopped.

 svc -d /service/qmail
 svc -d /service/qread
 svc -d /service/qstat
 svc -d /service/smtpd

OK let say that fails for some reason, here is a more bullyish approach.

 svc -k /service/qmail
 svc -k /service/qread
 svc -k /service/qstat
 svc -k /service/smtpd

Check qmail processes

 svstat /service/qmail
 svstat /service/qread
 svstat /service/qstat
 svstat /service/smtpd

(re)Start same

 svc -u /service/qmail
 svc -u /service/qread
 svc -u /service/qstat
 svc -u /service/smtpd

Check, stop and start djbdns (/dnscache/) processes

 svstat /service/dnscache
 /service/dnscache: up (pid 1336) 2421 seconds

 svc -d /service/dnscache
 svstat /service/dnscache
 /service/dnscache: down 3 seconds, normally up

 svc -u /service/dnscache
 svstat /service/dnscache
 /service/dnscache: up (pid 1869) 2 seconds

Regarding supervise, it may look in /service/, /etc/service/ or /etc/sv/

On Ubuntu it will be /etc/service/

Here are some of the more interesting svc flags

-u = up/enable 
-d = down/disable 
-t = restart
-k = kill (if -d doesn't work)