Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
[SOLVED]On boot, kernel cannot mount my ext4 root partition
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
pouete
n00b
n00b


Joined: 28 Oct 2012
Posts: 5

PostPosted: Sun Oct 28, 2012 2:55 pm    Post subject: [SOLVED]On boot, kernel cannot mount my ext4 root partition Reply with quote

Hello Gentoo !
So, i followed this wiki page :
http://www.gentoo.org/doc/en/gentoo-x86-quickinstall.xml
I added the ext4 file system in the menuconfig, recompiled and modules_install .
On startup, i have this error :
VFS: Cannot open root device "sdb1" or unknown-block(8,17)
Please append a correct "root=" boot option; here are the available partitions:
[...]
7878656 sdb1 0000000-0000-0000-0000-000000000
Kernel Panic - not syncing : VFS: Unable to mount root fs on unkown-block(8,17)
[...]
Here is my /boot/grub file :

title Gentoo Linux 2.6.24-r5
root (hd0,0)
kernel /boot/kernel root=/dev/sdb1 rootfstype=ext4

[EDIT] :
My sdb1 is ext4 and /
My sda1 is ext4 and /home/

If you need more details, feel free to ask !
P
_________________
Resistance is futile ( if < 1 Ohm )


Last edited by pouete on Mon Oct 29, 2012 11:21 am; edited 1 time in total
Back to top
View user's profile Send private message
BillWho
Veteran
Veteran


Joined: 03 Mar 2012
Posts: 1600
Location: US

PostPosted: Sun Oct 28, 2012 2:59 pm    Post subject: Reply with quote

pouete,

In grub device sdb would be (hd1,

Are you sure sdb1 is your root and not boot :?:
_________________
Good luck :wink:

Since installing gentoo, my life has become one long emerge :)
Back to top
View user's profile Send private message
pouete
n00b
n00b


Joined: 28 Oct 2012
Posts: 5

PostPosted: Sun Oct 28, 2012 3:13 pm    Post subject: Reply with quote

sdb1 is my /
/boot/ is located in my sdb1 .
/root/ is also located in my sdb1
only /home/ is on my sda1
about root(hd1, is it necessarily hd* or could it be something else ?
_________________
Resistance is futile ( if < 1 Ohm )
Back to top
View user's profile Send private message
toralf
Developer
Developer


Joined: 01 Feb 2004
Posts: 3686
Location: Hamburg

PostPosted: Sun Oct 28, 2012 3:31 pm    Post subject: Re: On boot, the kernel cannot mount my ext4 root partition Reply with quote

pouete wrote:

I added the ext4 file system in the menuconfig, recompiled and modules_install
You have to compile in the root fs type, didn't you did it ?
Back to top
View user's profile Send private message
pouete
n00b
n00b


Joined: 28 Oct 2012
Posts: 5

PostPosted: Sun Oct 28, 2012 3:40 pm    Post subject: Reply with quote

How could i perform/verify this ?
_________________
Resistance is futile ( if < 1 Ohm )
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 43192
Location: 56N 3W

PostPosted: Sun Oct 28, 2012 3:42 pm    Post subject: Reply with quote

pouete,

Your kernel loads and can see (8,17) which is /dev/sdb1 but not read what it finds there.
ext4 must be built into your kernel.


There are two causes, ext4 is not built into your kernel of what your kernel sees as /dev/sdb1 is not the same drive as the liveCD saw when you installed.
Drive reordering is common when you mix SATA and PATA drives in the same system.
_________________
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
pouete
n00b
n00b


Joined: 28 Oct 2012
Posts: 5

PostPosted: Sun Oct 28, 2012 5:11 pm    Post subject: Reply with quote

I tried to swap /dev/sdb1 and /dev/sda1
But the problem persists ( same error message, different values )
So, i suppose i need to compile my kernel with the ext4.
But, i already choosed the option such as explained here : http://en.gentoo-wiki.com/wiki/Ext4

how can i know if my actual kernel does support the ext4 ?

Regards
P
_________________
Resistance is futile ( if < 1 Ohm )
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 43192
Location: 56N 3W

PostPosted: Sun Oct 28, 2012 5:29 pm    Post subject: Reply with quote

pouete,

You can look in make menuconfig for the ext4 option. It must be set to <*>.or you can grep EXT .config
Code:
 /usr/src/linux $ grep EXT4 .config
CONFIG_EXT4_FS=y
CONFIG_EXT4_USE_FOR_EXT23=y
CONFIG_EXT4_FS_XATTR=y
# CONFIG_EXT4_FS_POSIX_ACL is not set
# CONFIG_EXT4_FS_SECURITY is not set
# CONFIG_EXT4_DEBUG is not set
CONFIG_EXT4_FS=y is for the ext4 filesystem.

You must remake and reinstall your kernel if you need to change it.
You must also *never* edit the .config by hand.
_________________
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
pouete
n00b
n00b


Joined: 28 Oct 2012
Posts: 5

PostPosted: Sun Oct 28, 2012 6:44 pm    Post subject: Reply with quote

Excellent !
Thanks NeddySeagoon,toralf and BillWho for the tips !
Here is how i solved my problem :
At the begenning, i was compiling my kernel with the ext4 configured with <M> as the selector ( i do suppose it means Module ?)
I just did all this :
http://www.gentoo.org/doc/en/gentoo-x86-quickinstall.xml
From the chrooting again, make menuconfig , selected ext with the <*> instead of <M> , compiled again , copied the new kernel of course and everything was working like a charm !

Thanks again for your time gentlemen !

Pouete
_________________
Resistance is futile ( if < 1 Ohm )
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