Disk Spindown Problem

[ThePol1]

I am running Ubuntu 10.10 (amd64). I have two SATA drives connected to the system that I use for weekly backups. I'd like to spin these two disks down when not in use. I have tried:

1) Editing hdparm.conf like so:

/dev/sdf {
spindown_time = 241
}

Result: The drives never spin down (checked them using hdparm -C /dev/sdf1)

2) I have also tried adding a line to rc.local like so:
sudo hdparm -S 241 /dev/sdf1

Result: The drives never spin down.

The drives are formatted as ext4. Here is how they are mounted in fstab:
UUID=(UUID) /media/(UUID) ext4 rw,suid,dev,exec,auto,user,async,relatime 0 2

I can't seem to find a way to spin these disks down. Any help would be appreciated.

[ian dobson]

Hi,

I imagine the problem is that the drives are mounted. All file systems write to the drivs every so often even if no application has written anything. So only mount the drives when your doing a backup.

I have 3 2tb wd drives in a RAID array that I use for backup, and I only mount the array when I'm doing a backup. I've kust checked and the drives are powered down at the moment. Also you should use the device name (/dev/sdf) not the partition number for hdparm.

Regards
Ian Dobson

[ThePol1]

That's it! I modified my backup script to mount (when it starts) and then umount (when it completes) and both drives now spin down. Thanks!

[ThePol1]

I spoke too soon. One of the drives spins down and stays in standby mode. The other drive spins down and then, after some time, spins back up... very strange since both drives are unmounted. Any thoughts?

[ian dobson]

Hi,

Could something be touching the drive/Smartdata or something like that.

When the drive powers up do you see anything interesting in the syslog (/var/log/syslog) or dmesg?
How often does the drive power up?
Are both drives setup exactly the same?
Maybe a different firmware on the drives?

Regards
Ian Dobson

[rubylaser]

I would bet it's the SMART daemon waking them up. If it is, here's how I set mine up to prevent SMART from waking up idle disks.

nano /etc/default/smartmontools

And add this...

smartd_opts=”-q never -i 7200"

I have changed it to check every 2 hours, and to not spin the drive up if it is in standby.

Finally,

nano /etc/smartd.conf

and add this to the edit of your DEVICESCAN line

-n standby,q