I have successfully installed qmail + vpopmail + qmailadmin on OpenBSD 2.6.
Everything works fine, but I have some questions related to tuning/managing
qmail:-
1. How do I restrict multiple simultaneous connections to a particular
server? Qmail works differently from other MTA's in that it opens a separate
connection for each message, even if there are multiple recipients on the
same domain. I have a situation where a user is sending a 1 MB file to about
10 people on the same domain, and qmail opens as many connections as it can
to that domain. However, some messages fail with a '554 transaction failed'
message. During the transfer I can do a netstat and will see that the rx/tx
queues have slowed or stopped, eventually leading to a fail (ps shows
qmail-remote processes active for longer than 4 hours!). Possibly the server
on the other end is having some trouble (of course, it's not *my* server
that has the problem ;). I assume that because qmail still seems to be
happily delivering mail to other servers at that time. The remote server in
question is running Webshield 4.0.3.1 from Network Assoc. I do not see a
similar problem if the message sizes are small.
2. The problem described above is new and has only occurred since we
installed qmail (I used to run Mailsite on NT). I do not know when last the
webshield server was changed/updated, so I cannot assume the the problem is
with qmail (we changed around the time lovebug was doing the lovin' thing
and no, that was not the reason). The Mailsite server is still active (need
ETRN), so I have added entries into smtproutes to try to direct mail for
that domain through the old server. However, after updating smtproutes, do I
have to signal any qmail processes (I assume not as the file is used by
qmail-remote, which is started each time a remote message needs to be
delivered). Where can I get a definitive list of actions that need to be
taken wrt qmail and its control files? A sort of
if-you-change-this,-then-do-that reference.
3. This is a really a *nix question. I need to allow more qmail-remote
processes. I know about the concurrency* files and what to do when they are
changed ;), but how do I increase the file handles allowed? Is the file
handle limit in place at the start of a process the limit that the process
inherits? Does that mean I should issue a 'limit' command in my rc.local
file (that's where qmail processes are started). Or if my main concern is
qmail-send, should the 'limit' command be placed just before qmail-start is
called? If anyone can recommend a book/resource on managing unix which
includes this type of information, I would appreciate it.
Thanks
Abdul
