Monitoring Disk Space
The one system resource that is most commonly over-committed is disk
space. There are many reasons for this, ranging from applications not
cleaning up after themselves, to software upgrades becoming larger and
larger, to users that refuse to delete old email messages.
No matter what the reason, system administrators must monitor disk
space usage on an ongoing basis, or face possible system outages and
unhappy users. In this section, we will look at some ways of keeping
track of disk space.
Using df
The easiest way to see how much free disk space is available on a
system is to use the df command. Here is an
example of df in action:
Filesystem 1k-blocks Used Available Use% Mounted on
/dev/sda3 8428196 4282228 3717836 54% /
/dev/sda1 124427 18815 99188 16% /boot
/dev/sda4 8428196 3801644 4198420 48% /home
none 644600 0 644600 0% /dev/shm |
As we can see, df lists every mounted file
system, and provides information such as device size (under the
1k-blocks column), as well as the
space used and still available. However, the easiest thing to do is
to simply scan the Use% column for any numbers
nearing 100%.
