USB drive mount disappears randomly, cannot remount (redhat 9)
 

I have a USB "bracket" around a plain old IDE hdd, it sits outside the pc. When I boot RedHat it detects it fine and it mounts fine.

I listen to mp3 tracks off that drive and it can work for hours or days when suddenly it stops responding and I cannot even do an ls on the drive.

I have tried unplugging the drive and then re-plugging it and doing a mount -a but I inevitably get a "mount: /dev/sda1 is not a valid block device" error.

I have tried rmmod usb-storage and then modprobe usb-storage but I am a newbie and clueless as to what those commands do - anyway they did squat.

If I do a tail /var/log/messages I get stuff like:
Dec 20 15:11:41 localhost kernel: usb.c: USB disconnect on device 00:10.3-3 address 4
Dec 20 15:11:41 localhost devlabel: devlabel service started/restarted
Dec 20 15:12:15 localhost kernel: hub.c: new USB device 00:10.3-3, assigned address 5
Dec 20 15:12:18 localhost /etc/hotplug/usb.agent: Setup usb-storage for USB product 7c4/ad01/104
Dec 20 15:12:19 localhost devlabel: devlabel service started/restarted

Where the USB device seems to get assigned address X, where X just keeps counting up. No amount of trying to mount against sdb, sdc, sdd seems to work - so I cannot fathom the connection between this "address" and the /dev/sd? nodes.

I would like the USB to stop failing, but if I could just have a little "recipe" to get it working again without restarting the machine that would be fine.

Specs:
fstab contains:
/dev/sda1 /mnt/usbdrv ntfs auto,ro,uid=donn 0 0
Drive is NTFS.
O/S RedHat 9.0
Kernel: 2.4.20-20.9
PC: AMD Athlon

Thanks.