Subject: Re: Mailbox corruption problem (procmail via sendmail) - HELP!

From: [email-masked] (Stephen R. van den Berg)
Date: Wed, 29 Mar 1995 15:46:07 +0200

"D.Ashton-Reader" <[email-masked]> wrote:
>My users quite often report corruption of their mailbox in the form
>of overlapped messages (in the system mailbox delivered by procmail
>involked from sendmail).  All mail is delivered on the same mailhub
>(called 'internet.cadcentre.co.uk' below) so it is not an NFS prob.
>except that users read their mail with various tools, (e.g. 'Mail')
>and they all read their mail via NFS, so that *may* be an issue.

This, most likely, is a locking problem.  There is a slight chance
that it is NFS related.

To test basic lock functionality, log in as one of the "problem" users,
then run:

lockfile -ml
Now send some mail to this user.
Now attempt to read the mail of this user using his usual mail reader.

If everything works as expected, there should now be a procmail process on
the mailserver (sleeping and waiting for the lock to vanish), and the
mail reader should stall (waiting for the lock to vanish).

Log in as this user on a second terminal, now run:

lockfile -mu

The procmail should be delivering the mail (within 8 seconds or so), the
mailreader should proceed.

If this works as expected, then NFS is the problem (procmail can deal with
it, but apparently the mailreader doesn't).

-- 
Sincerely,                                  [email-masked]
           Stephen R. van den Berg (AKA BuGless).

"Be spontaneous!"