Q:

External USB 2.0 drive formatted as ext4 periodically "freezes" if files are not read or written

I have an external USB 2.0 harddisk (Seagate 9SD2A2-500) that periodically "freezes" when files on the drive are not written to or read within approximately five minutes.  The drive is formatted as ext4, and I am running Ubuntu 10.04 LTS 64-bit.  
If I am editing a file that is stored on this drive, and I do not save the file every five minutes, an open application (such as gedit) will become unresponsive.  I must wait for at least a minute before the external drive becomes responsive again and the file can be saved.  I've also noticed this behavior when trying to access a file in Nautilus.
It appears that the drive is "falling asleep" and then "wakes up" after a certain time.  What is happening here, and is it possible to change this behavior?
I have another USB 2.0 harddisk attached to the computer.  The harddisk is formatted as FAT32, and does not show this behavior. 

A:

This is a "feature" rather than a bug related to power management of your external hard drive unrelated to formatting. Things you could try to do:
Disable harddisk power management from your BIOS.
Ask Seagate on how to disable power management on their external USB drives.
This is entirely not an Ubuntu issue.

