I have a customer with 4 500GB WD MyBook ext USB hard drives they use for backup. It doesn't matter which drive is connected, they all do the same thing. They will randomly disappear and then reappear. The drive is assigned drive letter F. It seems to happen when the drive is read. If I open the backup program and initiate a backup the drive disappears. If I wait for the drive to reappear and then kick off the backup manually it will work fine.
Things I've tried:
Different USB port on the server
Different USB cable
Turning off AV
Disabling non-essential software
Script that "wakes up" the drive by adding a small txt file to the drive before the backup runs
Disabled power management from shutting off USB devices
Any help is appreciated, thanks guys.