How to find the drive's rotational speed per minute (RPM)

[soorajspa...@gmail.com]

Hi,

1. Is there any SCSI command that I can use to find the RPM of a drive?? Please provide me the opcode.
2. Does sg3_utils has any specific utility for this?

Regards,
Sooraj

[Michael Baeuerle]

soorajspa...@gmail.com wrote:
>
> 1. Is there any SCSI command that I can use to find the RPM of a drive?? Please provide me the opcode.

AFAIK there is no special command available for that but there is a mode
page:

Rigid disk device geometry page (04h)

that can be read via MODE SENSE and that contains the field:

MEDIUM ROTATION RATE

If you don't habe the SBC document: The field has 16 bit size and starts
at byte offset 20. The unit of the data is RPM.

But note that this page is marked obsolete since SBC2 (approx. 2004) and
it is likely that modern SCSI disks don't support it anymore.

> 2. Does sg3_utils has any specific utility for this?

Any utility that can read mode pages via MODE SENSE should be
sufficient. Try one of the following utilities (untested):
- sginfo
- sg_modes
- sdparm