I recently purchased a G-S350SUAB external hard drive enclosure from our local Boise, ID Apple reseller. I purchased a Seagate 1TB Internal Hard Drive, model #ST310005N1A1AS-RK to insert into the enclosure.

I connected the drive via the Firewire 800 cable to my 24” iMac (early 2009) running OS 10.6.3 and formatted it to a Mac OS Extended with Journaling per the PDF instructions that came with the enclosure.

All went well, however the drive continues to spin down, then immediately spin back up and repeats this process when the screen on the iMac goes black or what I refer to as in activity. Eventually the iMac will go to sleep, but upon waking the computer the drive will not spin back up causing me eventually to do a hard shutdown of the computer.

To correct this I first attemted to go to the Energy Saver preference pane in System Preferences and uncheck the “Put Drives to Sleep” option under both the Power and UPS sections. This did not correct the problem.

I then went to the Terminal and completed a sudo pmset command to set the disksleep timer to 0, thus disabling the drives function to spin down. Unfortunately, this only worked for the internal drive and a USB drive connected.

I hunted high and low for a solution to my problem, when I came across an applet called Keep Drive Spinning 1.1. As the summary notates:

“This applet simply creates a launch agent that tells OS X to touch a hidden file on the selected drive once every minute so that the drive stays awake.”

Upon running this script I set the external drive to touch the hidden file every 30 seconds. Running it any longer did not correct the problem. This applet continues to run even after a reboot or restart.

As for the drive, it works well and houses my Home Directory.  The Firewire 800 connection much faster than the USB 2.0 connection I used in attempting to house the Home Directory on an exteral drive.  The Seagage drive is very quiet.

The one negative besides the drive spining off and on is the Blue LED light indicating the drive is powered.  I would prefer not to have this or have it located in the back.  Of couse this is only an issue when I am encoding something during the night.   Since that is on the rarest of occasions I believe I can live with it.

It should be noted I have sent an email to Macally technical support and hope to update this post with their response.

Update:  I took the enclosure back to the local Apple Reseller and spoke to the owner regarding the issue I was having.  As he put it “you have gone to way too much trouble, it sounds like the power supply in the enclosure has gone bad”  So I purchased another enclosure and it did the trick.  I will be taking the broken enclosure back for a full refund.