Linux commands and tips

Checking kernel & CentOS version

To check which kernel version you are running use uname -r

# uname -r

To find out which CentOS (or RedHat) release is installed have a look at /etc/redhat-release

# cat /etc/redhat-release

Checking Disk Space

To check disk space used / free use the df command and it will display each volume. The -h switch turns the bytes reading into GB to make it more readable.

# df -h

If you want to check the size of a particular directory then use:

# du -sh /