Put disabled HDD into deep-sleep mode

For EasyOS "Copy session to RAM & disable drives" mode, forum member 'MochiMoppel' has suggested that "hdparm -Y <drive>" be applied to the "disabled" drives. See forum thread:

https://forum.puppylinux.com/viewtopic.php?f=54&t=1583

HDDs, that is, magnetic-platter type, not SSDs, will go to sleep anyway, if unused for a certain time. The 'hdparm' utility can be used to adjust the timeout for that to occur. However, MochiMoppel says that to cut all the noise and power consumption, the drive should be put into deep-sleep mode, with the "-Y" parameter.

Documentation on the hdparm options can be found here:

https://www.linux-magazine.com/Online/Features/Tune-Your-Hard-Disk-with-hdparm

The deep-sleep mode may require that the computer be restarted, to bring out out of deep-sleep, and that is good from the security viewpoint. For that reason alone, as an extra surety that an intruder cannot find some way to access the drive, this is worth doing.

I have inserted some code into the 'init' script in the initrd, at line 1392:

#20201211 MochiMoppel has suggested use hdparm to power-down the internal drives...
if [ "$xWKG_DEV" ];then #note, in future could test for $LOCKDOWN instead of $xWKG_DEV
 if [ "$CAPS_DROP" ];then
  echo -n '' > /easy_new/root/.initrd-debug/hdparm-power-down
  REMDRVS="$(echo "$BLKIDS" | grep -o '^/dev/sd[a-z]' | sort -u | grep -v "${WKG_DRV}" | tr '\n' ' ')"
  for aREMDRV in $REMDRVS
  do
   HDDflg="$(cat /sys/block/${aREMDRV##*/}/queue/rotational)" #1 if magnetic platter drv, 0 if ssd.
   if [ "$HDDflg" == "1" ];then
    echo "Powering-down drive: ${aREMDRV}"
    echo "Powering-down drive: ${aREMDRV}" >> /easy_new/root/.initrd-debug/hdparm-power-down
    cttyhack /bin/hdparm -Y ${aREMDRV} >> /easy_new/root/.initrd-debug/hdparm-power-down 2>&1
    sleep 0.1
   fi
  done
 fi
fi

It seems to work, no error message, though I have no way of really knowing, except the drive should be dead quiet.

You can try this yourself:

1. Write easy-2.5.3-amd64.img.gz to a USB-stick
2. Boot the USB-stick, normal bootup
3. Click on the first partition of the USB-stick to mount it (that is the boot-partition)
   
4. Click on 'initrd' to open it up.
5. Click on file 'init' to launch in a text editor
6. Insert the above code, at line 1392 (just before "mount -o move /dev /easy_new/dev")
   
7. Save and exit the text editor
8. Click on file 'initrd' to update it.
9. Menu: "Shutdown -> Reboot, lockdown in RAM"
10. Tick "Copy session to RAM & disable drives" radio button, then reboot
    

Point-10, no need to tick the "Permanent" checkbox, as you only want to do it once, find out if it works. 

Changing the subject: In "Copy session to RAM & disable drives" mode, there is a "save" icon on the desktop. I created a file, then saved the session, but my file seemed not to have been saved. Will check this out ASAP. 

Tags: easy