WARNING: File Corruption Problem and how to deal with it

There is a major problem that afflicts people who use their removable hard disk in A306 and on the Compaqs in A204. Two people today have had their data become unreadable. What to do?

Interim solution

I recommend that everyone do the following when booting your disk after moving from A306 to A204 (or any Compaq computer):

press F10 to enter BIOS setup;
enter the password that your lecturer or technician gives you;
Change the setting for your removable hard disk (Primary disk 0) from "bit shift" translation mode to LBA translation mode;
Boot your system into single user mode. To do this with a grub boot manager (default with Red Hat 7.2), do:
- Use the arrow keys to navigate to the kernel you want;
- press the 'e' key to edit that entry;
- use the arrow keys to navigate to the kernel line;
- add the argument 1 to the end of the line to indicate that you want runlevel 1 (single user mode), and press return;
- press the 'b' key to boot.
remount the root file system read only:
```
mount -o ro,remount /
```
Then run the file system check on the partition:
```
fsck -f -y /
```
Then reboot your machine.

I will determine what is happening here so that we can prevent it in the future, but this is my recommendation for now.

The Probable Cause

The problem is most likely caused by incompatible disk geometry translation in the \BIOS of the computers in A306 and A204C\@. The technical details are here.

Nick Urbanik <nicku@vtc.edu.hk>

Last modified: Thu Mar 14 10:45:23 HKT 2002