Bug 148269 – Optical drive disappears when GRUB is installed on the MBR

• Product: Gentoo Linux
• Status: RESOLVED NEEDINFO

[Description Lenon Kitchens 2006-09-19 18:23:01 UTC]

I'm filing this bug here at the request of a moderator on the Gentoo forums.  This is NOT a Gentoo specific bug.  It happens with Mepis, Suse, Ubuntu and Gentoo at least.

I got a new laptop recently, specs to follow.  Upon receiving my new laptop I popped in the Windows CD and installed.  Everything worked great.  After installing Windows I installed a couple of games and some necessities for work, all from CD.

Once I was done with that, I popped in the Gentoo 2006.0 Live CD and did a fairly routine install.  A couple of days later while working in Windows, I noticed that my optical drive was missing.  I had noticed immediately that it wasn't showing up in Linux, but didn't have time to really look into it.  I just assumed that I had forgotten something that I needed in the kernel since it worked with the Live CD.  To make a long story short, I eventually realized that if I got rid of GRUB, the optical drive would magically reappear in Windows.  I even reinstalled and removed GRUB twice to verify these findings.

Machine Specs:
Clevo M570U (Clevo is a very popular laptop manufacturer.  Many machines are based off this model)
BIOS:  Phoenix TrustedCore 1.00
Chipset:  Intel 945PM + ICH7-M

Link to exact machine specs: http://www.clevo.com.tw/products/M570U.asp

Versions of GRUB tested: .96, .97 (tested several minor releases in each of those major releases)

Here is an excerpt from a discussion at: http://forums.gentoo.org/viewtopic-t-483634.html

The following post is mine and contains everything I know about this bug:

Many people are experiencing this problem. It never ceases to amaze me that people are always pointing to something within Linux as the cause of the problem.

The fact is, on these machines which include anything based on the Clevo m570U, the Clevo m575U and several others, this problem exists.

The trigger for the problem is in fact, GRUB. Whether grub is at fault, I do not know. Everyone seems to forget when trying to diagnose this problem that the simple act of installing GRUB on the MBR causes the drive to disappear from BOTH WINDOWS AND LINUX.

If you boot with your windows cd, drop to console mode and do a FIXMBR followed by a FIXBOOT, your drive will magically reappear in windows. No other Linux changes required. Of course, this is not a fix as you can no longer boot Linux.

I've heard this problem reported so far with Mepis, Suse, Ubuntu, Kubuntu, Mandrake, and Gentoo.

There are a few things that I can tell you about this problem.
1) If you pass acpi=off to the kernel via GRUB, the drive will show up, but only in PIO mode. This also causes a kernel panic sometimes after mounting the drive. The last message is something to the effect of the ata controller responding too slowly.

2) In all cases that I've seen where the problem manifests, the optical drive is set to slave and there is no master on the channel (it is impossible to change this setting on my machine).

3) If you have a second HDD that you can exchange for the optical drive and you set it to master, everything usually works fine. However, if you set it to slave as well you end up with the same problems that you had with the optical drive.

4) There are two consecutive lines in the output of dmesg...
PCI: BIOS BUG #81[49435024] found
ata2: disabling port
The BIOS bug message may or may not be related as it always appears. If you pass acpi=off to the kernel the
second line does not appear. This is when the drive works.

5) If GRUB is installed on the MBR, the only way to make the drive reappear in windows is to pop out the optical drive, and pop the second HDD (set to master) into the slot. Windows will find the second HDD on boot. Use the tray icon to "Safely remove hardware". After the second HDD spins down, pop it out and pop the optical drive back in. Go to device manager, find the entry for the HDD that used to be there, right click it and click "Scan for hardware changes". This will case the drive to appear. However, it's set to PIO only mode after this procedure and will disappear on reboot. I can't test it but I suspect that if the optical drive was set to master, this problem would not occur at least in Windows, possibly not in Linux either.

I hope this helps someone figure out what the hell is really going on here. IMHO, installing LILO, while it may work, is not a solution. There is a deeper problem somewhere.

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If you need any more information do not hesitate to contact me.

Thanks!

[Comment 1 SpanKY 2006-09-23 20:42:53 UTC]

you probably wont find help here ... you can try two things:
 - install grub-1.94
 - contact upstream

[Comment 2 Robin Johnson 2008-11-05 22:39:35 UTC]

Did lilo or any other alternative boot loader cause the same issue?
Please update on the status on your research.