[PLUG] Postfix hangs

[Keith Lofstrom]

I have postfix running on my vcolo gateway machine, processing about
12 mails (or spam attempts) per minute.  The machine is backed up over
the network at 430AM or so, saturating the bandwidth between that
machine and my site.   About once a week, during backup time, postfix
decides to hang and stop moving mail, leaving it queued up on the
vcolo machine rather than pushing it to the mail server on my site.
A "service postfix restart" causes the mail to start moving again.
I would like to figure out why, but there are no clues in 
/var/log/maillog or /var/log/messages on either machine (and the
maillog file runs to 20K+ lines due to all the spam,  so even 
hunting through it can take a long time).

The easiest way to resolve this is to automatically do the postfix
restart after the backup completes, but this seems awfully sloppy. 
Is there a clean way to jiggle postfix to remind it to keep working,
or else to figure out what is making postfix hang up so I can fix
the real problem?

Keith

-- 
Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs