HDD won't spin down

I am trying to setup a RPI3 based OMV NAS for a friend. His needs are very basic. He wants to backup pic from his phone whenever his phone runs out of space. The RPI is connected wire connected to the router. Speeds hit 11.5 MB/s and its sufficient to meet my friends need.

Two 320 GB Hitachi (HDT725032VLA380)hard disks are connected. They are inside a 2 bay USB case (a dual bay USB 3.0 case Ultra U12-43846).

I have one user on the NAS and on 320 GB HDD is exposed as a SMB/CIFS share.

Problem statement: The primary hard disk won't spind down after an access by SMB/CIFS user. But other hdd seems to be going into spindown.

If I reboot and have no activity then both HDDs will spindown. But SMB/CIFS access will wake up drive and then after that that HDD will never spindown.

Anyidea why the spindown is prevented?

Note: SMART monitoring is enabled. But disabling it makes no difference.

Thanks for the response. I did a manual "hdparm -Y /dev/sda" and "hdparm -Y /dev/sdb". I could hear the click and the drive spin down. No issues.

Also as I had reported in my original post, if I reboot and do no SMB/CIFS access, the drives would go into a spindown after about 10 minutes.

So it definitely is something on the pi thats keeping the disks from spinning down.

Thanks. I will look into it in the next few days and report on the progress.

I looked into the SMART polling time. My smart poll time is set to 3600 i.e. once every 60 minutes, if the drive is not in standby. So that is certainly not the issue. My HDDs are set to spindown after 10 minutes.

To better observe the behavior of the disks I moved the Pi and the disks to my desk. I can listen to the drives better this way. I have also connected a killawatt to monitor power changes.

After making these changes, I notice that after a few minutes, there is a click and the heads are likely parked at this time. I don't know why it does this, since its much less than the 10 minutes I set. Then after about 10 minutes the disks spindown. But its not spinning down completely.
I can also see the power coming down in steps. From about 19-20 when both HDD are in use to about 15W after heads are parked, and then finally to about 12W.

I wonder if its something set as a default in the HDD firmware? the default value for APM on this HDD is 0x01

Zitat von cabrio_leo

This is down by the USB to SATA bridge controller in the external USB case and independently to your spindown settings in OMV. This is a very common behavior of many USB cases as I have written above.

Wow, I did not know USB to SATA enclosures altered the drive behavior. Weird. I wonder why they would do it, rather than leave it to the OS or drive to behave in their default states.

Sorry my explanation was a bit unclear I guess. The heads first unload/park with a click about a minute or two after IO stops. Then about 9-10 minutes later the disk spins down. I can hear the spindown. But if I listen closely I can still hear the disk spinning. I think its going to a low RPM speed. It stays there infinitely.

Now if I issue a hdparm -Y command the disk fully spinsdown. This is corroborated by the power as well.

IO in progress on both hdd - 19-20W
Heads parked - 15W
Low speed spin - 12W
Full spindown after hdparm -y command - 8W.

Hope this clarifies.

@cabrio_leo thanks for the tip on hd_idle. I finally got around to trying your tip on the RPI NAS. Installed hd_idle and the disks now spind down completely. This is good.

One question: does hd_idle only spindown the disks when they are idle or does it just count down a time set in the config file and periodically issues a spindown command? I am a bit concerned that a spindown maybe issued in the middle of an io transfer operation.

Zitat von cabrio_leo

As the name "hd_idle" says, I assume that a spindown command is only issued when the disk is idle. Anything else doesn´t make any sense. In the readme of hd_idle one can read "hd-idle is a utility program for spinning-down external disks after a period of idle time". hd-idle utility, modified to use hdparm tool to spin down disks

I just went with the brief description on the github page that said "hd-idle utility, modified to use hdparm tool to spin down disks" I guess I should RTFM. :-). Thanks for the clarifications.