Red Hat Bugzilla – Bug 21901
diskcheck sends empty email if filesystem where tmp file is created fills up
Last modified: 2008-05-01 11:37:59 EDT
Because of the way the perl script /etc/cron.hourly/diskcheck.pl is written, by first creating a temp file and then emailing it, it will send an empty email if the filesystem where the $tempfile is to be created fills up. In rpm versions prior to diskcheck-3.1.1-10.6x, the $tempfile was created in /tmp. If /tmp filled up, root received an empty email. In the current rpm diskcheck-3.1.1-10.6x version, if /var were to fill up, you'd also get an empty email. This is from /etc/diskcheck.conf: # Location and name for a temp file $tempfile = '/var/spool/cron/diskusagealert.txt'; Suggest instead of creating the $tempfile and then mailing it, create the mail message in a local variable and then pipe that to the mail program. You'd do something like this in a shell bash script: # existing code to determine what filesystem is what percent full. # .... $msg = "The $filesystem is $percentage % full" echo $msg | /bin/mail root This should avoid the prior security issues with the $tempfile and allow you get an informative email when a filesystem is nearing capacity or is full. I'm not a perl programmer but if I have time, I might attempt to rewrite diskcheck and post it here. -scot
I just put a package in http://people.redhat.com/timp/RPMS which fixes the problem. Let me know if this works or not. Tim
I installed your package, ran the following to fill up /var: # dd if=/dev/zero of=/var/bigfile df now shows /var now at 100% # /etc/cron.hourly/diskcheck.pl No recipient addresses found in header
What is your $mailto set to in /etc/diskchek.conf? I'm able to send the mail just fine when doing a quick test as a regular user who doesn't have permission to write to /var/spool. Tim PS- the reason I haven't tested with a full var is because it's taking a while to fill it up for me. It will get tested though.
the default... # Who to mail to... $mailto = "root"; -scot
Might also mention I'm on a i386 RedHat 5.2 box with all the official RH updates. And if it makes any difference: I build the sendmail pkgs from RH rawhide SRPMS via 'rpm --rebuild' [root@rhwsa036 ~]# rpm -qa | grep sendmail sendmail-doc-8.10.1-3 sendmail-8.10.1-3 sendmail-cf-8.10.1-3 I built the perl 5.005 pkgs from RH 6.2 SRPMS via 'rpm --rebuild' [root@rhwsa036 ~]# rpm -qa | grep perl groff-perl-1.15-8 perl-DBI-1.07-2 perl-5.00503-11 -scot
Shouldn't matter. Change the mailto to this: "root\@localhost" That should do it. Tim
Please let me know if the change in mailto makes it work and I'll change it in the package. Tim
The problem is that when /var fills up completely (100%), sendmail has no room to write to /var/spool/mail and it produces the "No recipient addresses found in header" message. You also don't get the email message either, obviously. If /var does not fill to 100%, diskcheck.pl functions correctly and you do get an email when /var approaches capacity. I'd suggest shipping the updated RPM (the one from http://people.redhat.com/timp/RPMS/diskcheck-3.1.1-12.noarch.rpm ) with the following in /etc/diskcheck.pl: # Who to mail to... $mailto="root"; Thanks alot for the speedy response on this low priority issue. You guys Rock! Have a great day Tim! -scot