Finding problematic updates

I read about this tip from LINUX Format March 2009 Issue (page 83)

If you installed a software updates and something broke or no longer works, you may have to look at the Package Manager log File.

For Debian-based LINUX like Ubuntu, Linux Mint, the log file is /var/log/dpkg.log

For Redhat-based Linux like CentOS, Fedora, the log file is /var/log/yum.log

Reading generated logs in Real Time

Step 1: To help troubleshoot quicker, you may want to view the log in real time

# less /var/log/messages

Step 2: Press "F"

.....
.....
Waiting for data... (interrupt to abort)

Step 3: To exit, press
Ctrl+C
Alternatively, you can scroll forward or backward using "d" and "b" respectively.

VIewing Logs

I used to just view logs by doing "less /var/log/messages". But here is a more efficient way of viewing logs.

To show error on the /var/log/messages
# grep error /var/log/messages OR
# grep error /var/log/messages less

If you wish to view the contents of log in real time
# tail -f /var/log/messages grep error