====== Hard Disk Drive Power Management ======

===== Linux =====

Desktop hard drives often have fairly aggressive APM (advanced power management) settings configured by default.

Check your current drive's APM configuration (adjust device as needed):

<file>
hdparm -I /dev/sda |grep "Advanced power management level"
</file>

If you install 'desktop' hard drives in a server, you probably want to disable APM.  This might give you longer drive life at the expense of slightly higher power utilization.

Here we disable APM on ''sda'', ''sdb'', ''sdc'' and ''sdd'':

<file>
for x in [abcd]; do hdparm -B 255 /dev/sd$x; done
</file>

Here we add that command to ''rc.local'':

Here we disable APM on ''sda'', ''sdb'', ''sdc'' and ''sdd'' at startup:

<file>
cat << EOF >> /etc/rc.local
#
# Disable power management on all hard drives
#
for x in [abcd]; do hdparm -B 255 /dev/sd\$x; done

EOF
</file>

:!: The backslash keeps BASH from expanding the variable into ''rc.local'' and would be omitted if entering the command at the bash prompt.