Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
[solved]VFS: Cannot open root device "sdb6" or unknown-bl
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Installing Gentoo
View previous topic :: View next topic  
Author Message
almostnewbie
n00b
n00b


Joined: 29 Nov 2005
Posts: 3

PostPosted: Tue Nov 29, 2005 9:50 pm    Post subject: [solved]VFS: Cannot open root device "sdb6" or unk Reply with quote

Hello everybody!

I'm installing gentoo-2005.1-r10 amd64.

After finishing grub configuration, rebooted to get this:

Code:
VFS: Cannot open root device "sdb6" or unknown-block(0,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)


I've been looking around the forums and I think I understand that this problen involves device drivers included in the kernel. I've recompiled the kernel many times, last one with everything I could imagine was related to SATA drives. Also I'm pretty shure I'm including the fs support needed for ext2 & ext3.

The partitions in my hd (SATA 250gb, only one, don't know why is sdb and not sda):

sdb1 pri:fat32 data
sdb2 pri:ntfs winxp
sdb3 pri:ext2 /boot
sdb4 (extended)
sdb5 log:swap swap
sdb6 log:ext3 /
sdb7 log:ext3 nothing (later maybe another linux distro /)
sdb8 pri:fat32 data

I used root=/dev/sdb6 after the kernel in grub.

Anyone can help??


Last edited by almostnewbie on Fri Dec 02, 2005 7:25 pm; edited 1 time in total
Back to top
View user's profile Send private message
Telemin
l33t
l33t


Joined: 25 Aug 2005
Posts: 670
Location: Glasgow, UK

PostPosted: Tue Nov 29, 2005 10:00 pm    Post subject: Reply with quote

Try putting sda as the root option. I know it sounds wierd if the install disk put it down as sdb, but the kernel seems to do unexpected things sometimes....
_________________
The Geek formerly known as -Freestyling-
When you feel your problem has been solved please add [Solved] to the topic title.
Please adopt an unanswered post
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 31712
Location: 56N 3W

PostPosted: Tue Nov 29, 2005 10:03 pm    Post subject: Reply with quote

almostnewbie,

The unknown-block(0,0) means that your kernel cannot communicate with your hard drive.
This is normally because you have left out the kernel module for your motherboard chip set or the high level disc driver.

How did you configure and build your kernel?
Do you use an initrd file ?
You may also have an error in grub.conf.

Post the SATA line (all of it) from lspci, so we can identify your SATA driver.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.
Back to top
View user's profile Send private message
almostnewbie
n00b
n00b


Joined: 29 Nov 2005
Posts: 3

PostPosted: Wed Nov 30, 2005 4:56 pm    Post subject: Reply with quote

Hey! thanx for both replyes! ok,

Freestyling: I did what you said, very unthrustly (sorry, jeje :D )... but in fact it looks like it has worked! When I made the change, the boot process stoped here:

Code:

 * Mounting "this and that" ...       [ ok ]
   ...
 * Activating (possible) swap ...       [ ok ]
 * Checking root filesistem ...
fsck.ext3: No such device or address while trying to open /dev/sdb6
Possibly non-existent or swap device?
 * Filesystem couldn't be fixed :(       [ !! ]


At that point it asked me for root passwd for maintainance. The / filesystem was mounted read-only. Then I rebooted to the livecd, changed the entries in my fstab, all sdb's to sda's, rebooted and voila! login prompt!

Now I have a doubt: Why the livecd environment (wrongly?) asigned sdb to my drive, when there was no block device at sda? Could the fact of having it assigned that way at the time of configuraion, lead to some problems later? I mean, maybe something got configured to think there is a drive in sdb (and not in sda), because at config-time that was the situation...

Thanks again! and I'll wait for your answer.
Back to top
View user's profile Send private message
Telemin
l33t
l33t


Joined: 25 Aug 2005
Posts: 670
Location: Glasgow, UK

PostPosted: Wed Nov 30, 2005 5:35 pm    Post subject: Reply with quote

I think the only things that will be affected by that are grub and fstab, and since you've fixed both of those I very much doubt you will have any problems, since everything that runs in userland uses the references to the mounted filesystem rather than the devices themselves.

-Freestyling-

P.S please edit the topic title and add [Solved] to it.
_________________
The Geek formerly known as -Freestyling-
When you feel your problem has been solved please add [Solved] to the topic title.
Please adopt an unanswered post
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 31712
Location: 56N 3W

PostPosted: Wed Nov 30, 2005 5:54 pm    Post subject: Reply with quote

almostnewbie,

To add to what freestyling said, did you have some usb storage device attached during the install, is your CDROM SATA ?

Either of these features can cause the HDD to be moved away from /dev/sda.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.
Back to top
View user's profile Send private message
almostnewbie
n00b
n00b


Joined: 29 Nov 2005
Posts: 3

PostPosted: Fri Dec 02, 2005 7:20 pm    Post subject: Reply with quote

Hello both!

Yes, I had some USB connected during setup: a card reader. But that one is saw in windows like 4 usb systems, so my hd should have gone to sde, doesn't it? Also, my cd-rom is IDE, in fact, is recogniced as hda (is that correct?) so I think it may be another thing.

The other problem I have now is that now that I'm in my new environment I can't acces my cdrom drive, but if I can't solve that one myself, I'll post that in a new thread so others can find it.

Also, I hope that there is not going to be any other sda-sdb-mix-derived problem, like freestyling said, so I'll keep gentooing whit this install!!

If you have anything else to say, please do! If not, thank you both for your great help!!

BTW: is there any way to give credits to you for solving the problem in the forum, maybe something that gives you a higher rank or something?
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 31712
Location: 56N 3W

PostPosted: Fri Dec 02, 2005 8:01 pm    Post subject: Reply with quote

almostnewbie,

Your IDE drives will be /dev/hdX and your SCSI or SATA or usb-storage will be /dev/sdX
A card reader may not be the same as it is in Windows. Some only get a device special file when yhey have a memory module in.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Installing Gentoo All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum