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Can't boot from external USB hard drive


Posts: 3

I'm trying to install Mepis to an external USB hard drive. The installation to the partition sda2 formatted as ext3 seems to be OK, and I installed GRUB to the MBR (I'm not running any other OS).

But when booting from the USB drive failed - I kept on being returned to the GRUB menu editor. I found that GRUB had assigned hd(5,1) to the sda2 partition. That's understandable, as there are 5 hard drives inside the PC, so the USB drive would be 6th (therefore = hd(5,something) in GRUB). But on bootup the USB drive is the first drive, so I changed the menu entries to reference hd(0,1).

That got me further - I got to a screen which said audit(xxxx..xx) initialized. Then I got "Kernel panic - not syncing; VFS: Unable to mount root fs on unknown-block(0,0)."

How can I fix this?

What do you have in your

What do you have in your root= option in the kernel line? It should be root=/dev/sda2 or you could try not specifying the option at all.

root=/dev/sda2 is exactly

root=/dev/sda2 is exactly what I have. I'll try not specifying it as a last resort, as it's hard to see why nothing specified would work better than the correct parameter.

There are probably different

There are probably different ways of fixing this. One that may work, if you're running a kernel>=2.6.11, is adding the option rootdelay=10 to the kernel line. Have a look at:
http://www.mepis.org/node/8186
http://lists.debian.org/debian-powerpc/2005/12/msg00041.html

Having same issue, need some help.

i'm new wil linux, but having the same issues. Where would I go to make the changes listed here? Need paths, and files with an example for each preferrably.

Thanks,

Mac

The rootdelay=10 option is

The rootdelay=10 option is appended to the kernel line upon boot or, to make it permanent, appended to the kernel line in the Grub configuration file, /boot/grub/menu.lst. This file needs to be edited as root, can run kdesu kate /boot/grub/menu.lst.

rootdelay=10 option

I'll give it a shot,

Thanks,

Mac

still not working

1st,

My system sees the USB hard drive as a hard drive. If I leave it listed second after the internal hard drive, it makes it through the initial screen where it asks which os I want to boot.

I have kernel 2.6.10 however, and without being able to boot don't know how to get the 2.6.12 or higher. Could this be the problem?

I have edited the file to say rootdelay=10 as you said, and it does show up permanently now, but still have to use the CD to boot, so very slow.

Any ideas on what else to do. I still get the kernel panic error about HD0,0

Thanks,

Mac

You need a kernel >= 2.6.11

You need a kernel >= 2.6.11 to use rootdelay:

http://www.reactivated.net/weblog/archives/2005/11/booting-linux-userland-from-an-external-usb-flash-disk/

There is another fix for this, involving making a new initrd image, that can work in earlier kernels, I believe, but it's more involved and not something I've tried.

http://www.tummy.com/journals/entries/jafo_20050910_151334

With a kernel < 2.6.10, there's a chance you could get this to work without rootdelay or an initrd.

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