Question regarding 4.05-3 and virus scanner lock files

[Julian Field]

At 19:24 12/11/2002, you wrote:
>I have a few questions about the antivirus locking file mechanisms.  I'm
>running 4.05-3 on a Redhat test/development box with McAfee uvscan and found
>that the last time I sent a message, it made this lock file in
>/tmp/McAfeeBusy.lock :
>
># ls -alrt /tmp
>...
>-rw-------    1 root     root           50 Nov  11 17:33 McAfeeBusy.lock
>...
># cat /tmp/McAfeeBusy.lock
>Virus checker locked for scanning by mcafee 27087
>
>Process 27087 is still running (a MailScanner child), but there have been no
>messages coming into this machine (test box).  The last message received was
>around the same time the lock file was created.  The issue (I think?) is,
>whenever the last test message was sent through, the MailScanner checked the
>message for viruses, and left the lock file laying around.  Is this normal
>behaviour?

Yes. It doesn't bother deleting the lockfile as there is no need to.

>   Should it not unlock/unlink the file when it's completed?

It unlocks it, but does not delete it.

>   Are
>the MailScanner processes limited to running one copy of the virus scanner
>at a time?

No. MailScanner gets a "shared" lock on the file. Many shared locks can
exist at once. You can't have any shared locks while someone has an
"exclusive" lock on the file. The autoupdate scripts get an exclusive lock,
thereby excluding all the MailScanner processes while they update the virus
scanner.

>   Also, what happens when the mcafee-autoupdate script attempts to
>run -- will it bail and fail to run properly because the lockfile exists?
>I'm also considering changing the default lock file directory to /var/lock -
>there should not be any issues there, right?

You will need to set the location in the autoupdate script if you change it
in MailScanner.conf.

>P.S.  MailScanner is a wonderful thing!!

Thanks! Have you added a comment to the "guest book" on the web site yet?
--
Julian Field                Teaching Systems Manager
jkf at ecs.soton.ac.uk         Dept. of Electronics & Computer Science
Tel. 023 8059 2817          University of Southampton
                             Southampton SO17 1BJ