Magic: The disappearing hard drive trick

pwaller · 07-18-2006, 07:44 PM

I'm running the latest Ubuntu (6.06, 2.6.15-23-386).

The livecd boots fine, installing is fine. However, when I reboot and try to boot from hard disk, it isn't there.

Here is what I think is the relevant stuff from dmesg. (the full thing can be found at ht-tp://misc.randomphp.net/dmesgdat). The output to lspci can be found at ht-tp://misc.randomphp.net/lspcidat.

Code:

[4294672.063000] pata_get_dev_handle: dev_handle: 0xdfff9ca0, parent_handle: 0xc20d7ea0
[4294672.063000] pata_get_dev_handle: for dev=0x1f.2, addr=0x1f0002, parent=0xdff86a00, *handle=0xdfff9ca0
[4294672.070000] Driver 'sd' needs updating - please use bus_type methods
[4294672.074000] SCSI device sda: 195371568 512-byte hdwr sectors (100030 MB)
[4294672.074000] SCSI device sda: drive cache: write back
[4294672.075000] SCSI device sda: 195371568 512-byte hdwr sectors (100030 MB)
[4294672.076000] SCSI device sda: drive cache: write back
[4294672.076000]  sda:<3>ata1: command 0x25 timeout, stat 0xd0 host_stat 0x24
[4294702.076000] ata1: translated ATA stat/err 0xd0/00 to SCSI SK/ASC/ASCQ 0xb/47/00
[4294702.076000] ata1: status=0xd0 { Busy }
[4294702.076000] sd 0:0:0:0: SCSI error: return code = 0x8000002
[4294702.076000] sda: Current: sense key: Aborted Command
[4294702.076000]     Additional sense: Scsi parity error
[4294702.076000] end_request: I/O error, dev sda, sector 0
[4294702.076000] Buffer I/O error on device sda, logical block 0
[4294705.299000]  unable to read partition table
[4294705.299000] sd 0:0:0:0: Attached scsi disk sda

This is curious, because if I reboot the livecd, `ls /dev/sd*` just shows /dev/sda (not /dev/sda1, my root partition). Going into gparted, it correctly shows the partitions however with an exclaimation mark. If I delete and recreate said partitions, I can mount, access them and write and read files to and from them. ls correctly lists /dev/sda1. So it seems gparted is doing something when it performs the reformat/repartition that correctly sets up access.

As soon as I reboot, it all becomes inaccessable, I haven't found a way of getting to them yet.

I have consulted quite a few people on the subject and they seem to think this behaviour is very strange. I have actually submitted a bug report to ht-tps://launchpad.net/distros/ubuntu/+bug/53385 - this may contain more information. Does anyone have any ideas? Thanks in advance.

(remove the '-'s from the http links because it wouldn't let me post them until I've made three other posts..)

- Peter.

DaneM · 07-19-2006, 01:37 AM

Hi, Peter.

This is, indeed, a very strange problem. What boggles me a bit (and makes me think that it could be a bug in Ubuntu's implementation of parted/gparted, or perhaps fdisk) is that when you reboot, the partition goes away. One way to rule out a software problem is to try it with different software.

Download Knoppix from www.knoppix.org and burn it to a CD. (Here's hoping that you have another computer you can do this with.) Boot from the Knoppix CD and use QTParted (the KDE version of GParted), or just plain parted (from the command line, as root) to set up your partitions on /dev/sda. Copy some stuff to the partition(s) you create and reboot, logging once again into Knoppix. Now try to access the files you put on the partition(s) you created. If it works, chances are that it's a problem somewhere in Ubuntu (and you should post all this, including what you did to make it work, on the bug tracker). If it doesn't work, it's probably a hardware problem.

If knoppix has trouble seeing your hard drive (unlikely), try looking at the boot options when you first start up with the Knoppix disk in the drive. There may be something in there about SCSI or SATA that you should use (assuming that you're using a SCSI or SATA drive).

If you can get the partitions to "stay put" using Knoppix, there's still hope for installing Ubuntu: partition them in Knoppix, and then just tell the Ubuntu installer where you want the mount points to be.

Let me know how it goes.

--Dane

pwaller · 07-19-2006, 02:31 AM

Okay, trying this. Gonna take an hour or so to download.

[edit]

It didn't make a difference, but while doing the download I found qtparted under ubuntu, and tried the same process as described above. The knoppix ISO should be done in about 1 minute, I'll probably be trying to install it over the next half hour.

pwaller · 07-19-2006, 04:39 AM

well, I just successfully booted knoppix and it found and automatically mounted /dev/sda1, and the files I created from within the Ubuntu livecd were there.

So does this confirm it to be a Ubuntu bug, is there anything I can do about it?

Is it useful for the Ubuntu bug tracking list to know about this?

- Peter

DaneM · 07-19-2006, 05:53 PM

Hi, Peter.

At least it's not a hardware problem. :-)

I would definitely report it to the Ubuntu bug tracker, including a detailed description of what did and didn't work. It may even be a problem with udev or something like that.

You may, however, be able to find a workaround so that you can get your Ubuntu installation up and running. If you would like to give that a shot, please post the contents of /boot/grub/menu.lst, /boot/grub/device.map, and /etc/fstab on your /dev/sdax partition (where x is the "/" partition that Ubuntu will be using). Note that you must have Ubuntu installed on that drive in order to get these files off of it (although you can use Knoppix to access them).

Alternatively, you can download and install from the Ubuntu Alternate CD. This doesn't boot into a live CD, and has a text-based installer (ncurses), but is capable of doing more stuff (perhaps in a better fashion) that the default Desktop CD.

Have a good one.

--Dane

pwaller · 07-20-2006, 08:36 AM

After much, much faffing (I spent almost two days solid on this), I ended up building the lastest kernel from scratch from within Knoppix. This has fixed the problem and I'm now talking to you from my new installation. Whoopie!

Although building a kernel from scratch isn't exactly a satisfactory solution, mind.

I did report this to Launchpad but I doubt they'll do anything about it.

- Pete

DaneM · 07-20-2006, 03:21 PM

I'm glad you got it working! Ubuntu is a great distro.

Since this is a pretty severe problem from a useability standpoint, I imagine they'll get on it pretty soon. Or maybe not.

Have a good one.

--Dane