Here's what iSlayer support had to say. I can understand the performance hit is due to scheduling long selftests, but is there something to what they are saying? Does enabling SMART doesn't start an automatic test schedule for certain drives?


You're correct that we disable S.M.A.R.T. when monitoring the temps. We believe this is the correct thing to do.

Here's a comment from Apple's sample code:
"// Now that we're done, shut down the S.M.A.R.T. If we don't, storage takes a big performance hit."

I hope that helps shed some light on why we've taken the path we have.



On Sun, Jul 26, 2009 at 11:20 PM, Trevor Hart <> wrote:

I had already thought about the software angle and had made doubly sure nothing was in cron or elsewhere that might be interfering. I had stayed plugged in and altered that preference already to minimize any issues related to the OS parking the drive.

However, your note prompted me to rethink about everything running, I realized I have Slayer's iStat menus installed. It polls for for drive temperature using SMART, and it must be disabling it. Disabling that check leaves the drive enabled.

Many thanks for pointing me in the right direction.

I'll post back when I hear something from the developers.


On Sun, Jul 26, 2009 at 10:05 PM, Geoff Keating <> wrote:

On 26/07/2009, at 3:40 PM, Trevor Hart wrote:

Hi all,

I'm running smartmontools 5.38 on Mac OS 10.5.5.

I'm able to kick off self tests and view their results, but for some reason the drive will revert back to:

SMART support is: Available - device has SMART capability.
SMART support is: Disabled

after a matter of time.

The drive in question is:

Device Model:     FUJITSU MHZ2320BH FFS G1
Serial Number:    K67BT9226SAW
Firmware Version: 00810091

I've submitted it to the database list already, but I'm really stumped why the drive will not stay enabled. I'm not powering off the machine or letting it go to sleep; it will revert to disabled in a matter of minutes.

Just curious if there's another way to diagnose this issue or if I should reach out to Fujitsu support.

Do you have any other software installed that might be disabling SMART on the drive periodically?

You might also try turning off "Put the hard disk(s) to sleep when possible" in the energy saver control panel, just to see if that makes a difference.  Perhaps the drive isn't properly saving the SMART state when it goes to sleep.