Wietse Venema:
> 3) Instead of changing the file system layout, we could change
> master.cf to use "unix" instead of "fifo" endpoints for the queue
> manager and pickup services. The reason for using FIFOs is that
> Solaris 2.4 UNIX-domain sockets locked up the kernel during
> Postfix tests (the change to FIFOs then exposed bugs in several
> 4.4BSD implementations, but I disgress).
>
> To this date, both the trigger client (used in postdrop and cleanup)
> and trigger server (used in qmgr and pickup) contain code for
> UNIX-domain sockets. This code has not been tested in 12 years,
> so minor updates are likely needed. But the benefit of this is
> that there are no visible changes except four bytes in master.cf.
I just checked: this code works fine on FreeBSD, and I expect no
surprises on Linux.
With this, there are no "write" operations under the "public"
directory once Postfix has been started, so the disk should
not spin up due to mtime changes.
However, this can't be used on Solaris until it can be demonstrated
that their UNIX-domain sockets are up to the job (and even then,
one has to allow for the existence of Solaris systems that do
not run the latest and greatest. So I will be stuck supporting
multiple IPC models.
Wietse
> I would prefer the third solution, as it introduces no external
> dependencies on boot scripts to mount and populate spool/postfix/run,
> and it introduces no visible changes to the file system layout.
>
> > I'm fine to change postfix-files locally so it looks at
> > run/pid etc instead of pid, but that appears to be a bit
> > ugly...
>
> I don't understand why this is needed at all. On my own systems,
> "ls -lat /var/spool/postfix/pid" shows that there are no writes to
> the directory itself or to any files in that directory after the
> mail system has started up.
>
> Wietse
>
