Steve Jenkins:
> As far as parallel submissions, we're only doing three at a time
> (three SwiftMail processes sending at a time). Our in_flow_delay
> parameter is set to 0. We aren't receiving a lot of mail on this box,
> so I'm not sure that delay would even kick in if it were set to the 1s
> default. Beyond this, we're not sure how to check to see if the disk
> is being "overwhelmed with mail submissions." Out iowait% is 0.23, so
> the CPU isn't waiting for the disk. How else can we tell if we're
> overwhelming the disk?
Because the disk is 100% busy according to whatever your system
status tool is. One symptom is that delivery rates drop when you
increase the input flow.
With good hardware and other preparation, Postfix can make hundreds
of deliveries per second, as observed first-hand by Victor.
Wietse
