How to read hard disks temperature

hddtemp utility will give you the temperature of your hard drive by reading data from S.M.A.R.T. on drives that support this feature. Only modern hard drives have a temperature sensor. hddtemp supports reading S.M.A.R.T. information from SCSI drives too. hddtemp can work as simple command line tool or as a daemon to get information from all servers.

Installation:

Opensuse - Go to yast >> Software management and search for "hddtemp", select the package and accept and install it.

Others:
You can also perform source code installation. Download source code here.
Copy the tarball into the /usr/src/ directory on your linux box. From a command prompt, change into the /usr/src/ directory, and un-tar the tarball:

cd /usr/src
bunzip2 hddtemp-0.3-beta15.tar.bz2
tar xvf hddtemp-0.3-beta15.tar

Change into the newly created directory:

cd hddtemp-0.3-beta14

Compile and install hddtemp:

./configure --with-db-path=/etc/hddtemp.db
make
make install

Getting Data
The next task is to verify that hddtemp can retrieve the temperature from your hard drives.
Test hddtemp by running the following (replacing /dev/sda with a valid hard drive in your linux box):

 # hddtemp /dev/sda
/dev/sda: ST3802110A: 46°C

and see if a temperature is reported.

If you have more than one hard drive in your linux box, repeat this for each additional physical hard drive, to determine which ones hddtemp can obtain a temperature reading.