Hdparm - Checking if a drive is spun down

Question

Is there anyway to find out if a hard drive has spun down? I've been using the following command to spin it down after idle time:

hdparm -S 120 /dev/hdX

However im not sure it's working correctly and was wondering how to check the current power state to see if has correctly powered down.

Thanks

Answer 1

You can find out the power status with the -C flag to hdparm:

hdparm -C /dev/hdX

As explained by man 8 hdparm:

-C

Check the current IDE power mode status, which will always be one of unknown (drive does not support this command), active/idle (normal operation), standby (low power mode, drive has spun down), or sleep‐ ing (lowest power mode, drive is completely shut down). The -S, -y, -Y, and -Z flags can be used to manipulate the IDE power modes.