How To Find Hard Disk (RPM) speed

How do I check my hard disk Revolutions Per Minute (RPM) speed from a Linux shell prompt without opening my server case? any other third party utility please let me know.

I referenced some other articles. they give only model number, serial number and disk space, but I need Hard disk RPM speed using shell script. any other Java program

Solution 1:

# hdparm -I /dev/sda | grep Rotation

Nominal Media Rotation Rate: 7200

Solution 2:

If you want to know the disk's actual RPM, analyze the sound. An X rpm drive will have a noise peak at (X/60) Hz.

Some models report this information through SMART:

# smartctl -i /dev/sda
…
Rotation Rate:    5400 rpm
…

If not your best bet would be to obtain the disk vendor and model (e.g. from /sys/block/sda/device/model) and look it up.

The rpm figure is pretty useless, though. Are you sure that's what you're after? What are you trying to achieve?