I just spent a few hours of insanity seeing what that can do if mails not turned off if you don't use it....you can run out of server space. Most of my domains had it set to being off, but on some domains, I had missed turning it off, and SPAMers found out that E-mail wasn't being returned, so they were sending E-mail to the domains. One domain had over a Gig of E-Mail, er SPAM, just waiting to be checked. What can a server do to your sites if it has no space? I found out about this by seeing my vBulletin boards spit out a connection error message. So I rebooted and then to my horror, less than 10 minutes later it did the same thing. Then it got really bad. Tables started geting corrupt when you did stuff that tryed to add stuff to them...like post or send PMs! I tried phpMyAdmin for repairing them...and that made more corrupt!!! Next I tried it in SSH and that worked, but soon they would get corrupt again!!! I finally went to vBulletin and made a thread about it, even though it wan't just my vBulletin site that was messed up, hoping the errors would tell one of the support guys what it was. And bam, got a reply in just four minutes with the answer... Error code 28: No space left on device No space was left!!!!! Then I finally went hunting for the huge files to empty, and emptied logs and E-mail files, geting 10 Gigs of stuff deleted.
This will always serve as heads up to those system admins. And please dont forget the df -kh . Thank You for the sharing, I will really take note of this
And when you run out of space, in SSH, do cd / du -h --max-depth=1 It will list the directories showing how much space they take up. Then work your way through the directory that takes up most of the space. I made my way to a log directory and found.... 48G ./audit.d /var/log/audit.d was taking up 48 Gigs!!!!!!!!