Arch Linux

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

hard drive mounting problem.

hey everyone, I just installed arch on my laptop. I wanted to install on my external usb hard drive. I unplugged my internal hard drive (with windows) on it for the install, since I was kind of paranoid about ruining something. So during the install the only drive was the external which was identified as sda, great. Everything works fine when the internal is not plugged in.

When I have the internal plugged in and try to boot I get the nasty error message about not being able to mount sda and not finding something or other, kernel panic. Obviously the internal is being identified as sda now so it is looking there. How do I change this, so it looks in sdb (the external) to find the stuff to boot? Thanks for the help

jacko

Member

Registered: 2007-11-23

Posts: 840

Re: hard drive mounting problem.

change your bios settings to boot the usb external drive first. that should putt external back to sda device.

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

Re: hard drive mounting problem.

The thing is, GRUB is installed on the externals MBR. I;m getting to grub, and arch is starting to boot. About 10 seconds into the boot I get a message about kinit trying to find an init file. Kinit is looking for the init file on sda, but the file is located on sdb. How can I change this?

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

Re: hard drive mounting problem.

Just had a thought, could this be a problem with /etc/fstab ? I guess I will try editing that and changing everything to sdb, hopefully that will fix it. I will post back here when I finish.

stingray

Member

From: Lima, Peru SA

Registered: 2006-03-24

Posts: 188

Re: hard drive mounting problem.

when you first the the Gurb menu, enter 'e' to edit the commands.
You will then see three lines, use 'e' again to edit the lines...
change the first one to from (hd0,0) to (hd1,0)
change the second one from root=dev/sda1 to root=sdb1

then enter 'b' to boot...

Once in your system, edit /boot/grub/menu.lst to match the changes..., then reboot and test again...

That is the basic idea.  Good luck!

Last edited by stingray (2008-02-20 03:20:42)

stingray

Member

From: Lima, Peru SA

Registered: 2006-03-24

Posts: 188

Re: hard drive mounting problem.

Just had a thought, could this be a problem with /etc/fstab ? I guess I will try editing that and changing everything to sdb, hopefully that will fix it. I will post back here when I finish.

Yes, good catch, but for GRUB, edit the /boot/grub/menu.lst

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

Re: hard drive mounting problem.

hmmm now I am not even getting as far as last time. Heres some of the error messages

Device /deb/sdb1 does not exist attempting to create it
ERROR:Failed to parse block device name for '/dev/sdb1'
ERROR:Unable to create/detect root device  '/dev'sdb1'
Dropping to a recovery shell

Once I navigate to /dev and list the stuff in there from the recovery shell I can see sdb1, and its definately the correct partition.
Any ideas of what could be going wrong?

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

Re: hard drive mounting problem.

I am also getting a message that I should be using the "rootfstype=" option for the kernel.

stingray

Member

From: Lima, Peru SA

Registered: 2006-03-24

Posts: 188

Re: hard drive mounting problem.

Just another thing to try: try editing the /etc/mtab file also to match your sdb changes...  Again, good luck, don't give up.

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

Re: hard drive mounting problem.

Well I got farther now. Thanks for the help. I used the rootfstype=ext3 option and that got me past where I was. So now Im at the part where arch does "checking filesystems" and it is checking /dev/sda. I need it to check for /dev/sdb so this must be a problem with mtab of fstab. I will look into it.

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

Re: hard drive mounting problem.

OK so the problem is in /etc/fstab but I can't seem to find a way to edit it.
The only way I can get to a shell that has nano or another editor in it is to mount the hdd during boot as read only, so I can't edit there.

If I try to edit the fstab file by using the livecd it looks totally different, I have no idea why. I used the live cd to mount the drive and tried to edit it but none of the normal lines showed up. Is this file created at boot time?

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

Re: hard drive mounting problem.

Well I got the fstab file changed, but now I'm back to square one because the GRUB options I was using earlier are no longer working. It recommends that I add some time to wait so /dev/sdb can be "created"

JohnnyBoy022

Member

Registered: 2008-02-20

Posts: 12

Re: hard drive mounting problem.

Well this time it worked, after I turned my computer completely off. Something wasn't getting unmounted correctly I guess, but its working now so I have no complaints. Thanks for the help.