Linux & Sysadmin openstack and kvm journal

Hi folks,
Here is the quick fix to the apache permission denied error:

Go to users public_html folder and do this:

find . -type d -exec chmod 0755 {} \;
find . -type f -exec chmod 0644 {} \;

Another useful tool to find and replace string in all files in subdirectories.

find . -type f -exec
  sed -i 's/foo/bar/g' {} +

Quick solution for searching string among the ps aux result and kill all processes matching the name.

ps -ef | grep "UID SEARCH" | 
 grep -v grep
 | awk '{print $2}' | xargs kill -9

Spam sending by one of Your users may have significant impact on the server's performance and ip reputation.
Here's the simple bash script to monitor the queue.

#!/bin/bash
if [ `/usr/sbin/exim -bpc`-ge 100 ]; 
then
mail -s "Alert: Over 100 Emails 
 in the queue!" mail@example.org << EOF
Current Mail Queue :
`/usr/sbin/exim -bpc`
`/usr/sbin/exim -bp | /usr/sbin/exiqsumm`
Thanks,
EOF
fi

High load can be caused by other factors too. By editing the script above You can monitor the load itself.

#!/bin/bash
r=$(cat /proc/loadavg
 | awk -F. '{print $1}')
if [ $r -ge 7 ]
then
mail -s "Alert: Server load over
 $r!" mail@example.org << EOF
Server load over $r
`/usr/bin/ps aux`
`/usr/bin/sar`
EOF
fi