Determining if a drive is in standby mode

[NASbox]

When I upgraded my FreeNAS box, I installed an LSI HBA, so now I have drives that are daX, and adaX. I have a script that checks to see if a drive is spun down (I have a secondary pool that is rarely used and stays in power down standby) and not wake it up just to take it's temperature.

I got the camcontrol code from one of the forums here, but I have no idea what that string of bytes is all about or exactly how this command works. I assume camcontrol is sending that string of bytes to the disk drive, and those bytes are some sort of command to generate a status report???

Code:

adastat () { echo -n `camcontrol cmd $1 -a "E5 00 00 00 00 00 00 00 00 00 00 00" -r - | awk '{print $10 " " ; }'` " " ; }

The reason for this post is that this command works fine on the adaX drives, but the daX drives (LSI HBA) cause it to choke.

Any suggestions? Thanks.

 

[MrToddsFriends]

Maybe this thread helps (smartctl way to check if a drive has spun down because the camcontrol way dosn't work if "drives attached through a card"):
https://forums.freenas.org/index.php?threads/how-to-let-drives-spin-down.26314/

I never used the script discussed there myself.