Partitioning a My Passport 500GB hard drive and Ubuntu Linux

I just purchased a My Passport 500 GB external hard drive to run Linux Ubuntu operating system on.  Everything is set up and I’m able to dual boot either into Win 7 from my internal drive or boot into Ubuntu Linux on the external hard drive.  Problem I’m having is after several minutes the external hard drive shuts down as if going into sleep mode and I’m no longer able to access the drive without powering off the computer and back on again. Then I’m able to use the hard drive again for a few minutes. 

When I boot into Win 7 and run my diagnostics that I received from Western Digital support site it passes with flying colors and drive goes to sleep and wakes up without a problem. 

Is there anyone familiar with Ubuntu Linux and knows of a wakeup command to send to wake the drive up while using linux operating system?

Don’t know if it will work in your case, but you can try installing smartware and disable the sleep mode.

I looked at that web site and found that WD does not support external hard drives running Linux.  They say many external drives will run but you need to find which one by contacting your Linux distribution people.