Mailing List Archive: RE: Suse 9.3 "kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block (8, 1)"

RE: Suse 9.3 "kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block (8, 1)"

Jun 14, 2005, 1:15 PM

Post #1 of 7 (1181 views)

It's possible that the fstab is incorrect inside your image. Make sure
it is mounting / as /dev/sda1.

David

-----Original Message-----
From: xen-users-bounces@lists.xensource.com
[mailto:xen-users-bounces@lists.xensource.com] On Behalf Of e&v
Sent: Tuesday, June 14, 2005 3:12 PM
To: xen-users@lists.xensource.com
Subject: [Xen-users] Suse 9.3 "kernel panic - not syncing: VFS: Unable
tomount root fs on unknown-block (8, 1)"

hi, hope you can help or at least give me a hint how to proceed.... I
have Xen up and running with a domain0 but having huge problems in
getting additional domains created.

I followed the instructions in the Suse "readme for xen packages " ->
http://www.suse.de/~garloff/linux/xen/README.SuSE and I get to e)

These are the steps I followed:
Ad 3) YaST dirinstall
a) Create a root FS image
- create disc image file (dd if=/dev/zero of=img ...)
- create file system (mkXYZfs img)
- mount image (mount -o loop img ...)
b) start yast2 dirinstall module, select mounted directory as a target,
select required packages (don't forget to select XEN kernel, you
need
some of the kernel modules in the root FS)
c) create /etc/fstab in the root FS
d) umount image/FS
e) configure and start XEN (use the image/FS as storage)

When I use the config below, when starting a new domain with

xm create configfile vmid=1 -c .... I get the following error in the
start up sequence:

"kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block (8,1)"

Config.file:
kernel = "/boot/vmlinuz-2.6.11.4-21.7-xen"
memory = 100
name = "suse931"
nics = 1
ip = "1.2.3.4"
disk = ['file:/home/name/vm1disk,sda1,w']
root = "/dev/sda1"

By the way I get the same error when trying to start TTYLINUX ... and I
followed the instructions in the Xen Manual
(http://www.cl.cam.ac.uk/Research/SRG/netos/xen/readmes/user/user.html#S
ECTION02330000000000000000

--

ciao ev

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Re: Suse 9.3 "kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block (8, 1)" [ In reply to ]

ervin23 at gmail

Jun 14, 2005, 1:21 PM

Post #2 of 7 (1174 views)

Permalink

hi david & thanks,

the fstab is changed within the image to root / as /dev/sda1 :-) and
I assume that the ttylinux file rootfs.gz has the same root device
"/dev/sda1" (... you can't change it anyway)

ciao

On 6/14/05, David_Schmidt@dell.com <David_Schmidt@dell.com> wrote:
> It's possible that the fstab is incorrect inside your image. Make sure
> it is mounting / as /dev/sda1.
>
> David
>
> -----Original Message-----
> From: xen-users-bounces@lists.xensource.com
> [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of e&v
> Sent: Tuesday, June 14, 2005 3:12 PM
> To: xen-users@lists.xensource.com
> Subject: [Xen-users] Suse 9.3 "kernel panic - not syncing: VFS: Unable
> tomount root fs on unknown-block (8, 1)"
>
> hi, hope you can help or at least give me a hint how to proceed.... I
> have Xen up and running with a domain0 but having huge problems in
> getting additional domains created.
>
> I followed the instructions in the Suse "readme for xen packages " ->
> http://www.suse.de/~garloff/linux/xen/README.SuSE and I get to e)
>
> These are the steps I followed:
> Ad 3) YaST dirinstall
> a) Create a root FS image
> - create disc image file (dd if=/dev/zero of=img ...)
> - create file system (mkXYZfs img)
> - mount image (mount -o loop img ...)
> b) start yast2 dirinstall module, select mounted directory as a target,
> select required packages (don't forget to select XEN kernel, you
> need
> some of the kernel modules in the root FS)
> c) create /etc/fstab in the root FS
> d) umount image/FS
> e) configure and start XEN (use the image/FS as storage)
>
> When I use the config below, when starting a new domain with
>
> xm create configfile vmid=1 -c .... I get the following error in the
> start up sequence:
>
> "kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block (8,1)"
>
> Config.file:
> kernel = "/boot/vmlinuz-2.6.11.4-21.7-xen"
> memory = 100
> name = "suse931"
> nics = 1
> ip = "1.2.3.4"
> disk = ['file:/home/name/vm1disk,sda1,w']
> root = "/dev/sda1"
>
> By the way I get the same error when trying to start TTYLINUX ... and I
> followed the instructions in the Xen Manual
> (http://www.cl.cam.ac.uk/Research/SRG/netos/xen/readmes/user/user.html#S
> ECTION02330000000000000000
>
> --
>
> ciao ev
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>

--

mvh/best regards ervin

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Re: Suse 9.3 "kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block (8, 1)" [ In reply to ]

tbrown at baremetal

Jun 14, 2005, 1:37 PM

Post #3 of 7 (1162 views)

Permalink

On Tue, 14 Jun 2005, e&v wrote:

> hi david & thanks,
>
> the fstab is changed within the image to root / as /dev/sda1 :-) and
> I assume that the ttylinux file rootfs.gz has the same root device
> "/dev/sda1" (... you can't change it anyway)
>
> ciao
>
> On 6/14/05, David_Schmidt@dell.com <David_Schmidt@dell.com> wrote:
> > It's possible that the fstab is incorrect inside your image. Make sure
> > it is mounting / as /dev/sda1.

No, this:

> > "kernel panic - not syncing: VFS: Unable to mount root fs on
> > unknown-block (8,1)"

means that the kernel could not recognize /dev/sda1

(8,1) comes from the major and minor numbers, e.g. :

[root@am3 ~]# ls -ld /dev/sda1
brw-rw---- 1 root disk 8, 1 Mar 23 2001 /dev/sda1

this would _not_ be an fstab issue, as the boot process has not
gotten that far yet.

> > disk = ['file:/home/name/vm1disk,sda1,w']
> > root = "/dev/sda1"

are you _sure_ that "/home/name/vm1disk" is correct? and can you
mount it via loopback (my apologies if this has been covered).

"name" seems pretty generic, I suspect you haven't changed it to
your userid, or updated it for the path on your system?

"unknown-block" sounds bad... like it isn't there, as compared to
being misformatted or the like.

-Tom

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Re: Suse 9.3 "kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block (8, 1)" [ In reply to ]

dfbp at us

Jun 14, 2005, 1:47 PM

Post #4 of 7 (1174 views)

Permalink

> > disk = ['file:/home/name/vm1disk,sda1,w']
Try using '0801' instead of sda1

On Tue, 2005-06-14 at 13:37 -0700, Tom Brown wrote:
> On Tue, 14 Jun 2005, e&v wrote:
>
> > hi david & thanks,
> >
> > the fstab is changed within the image to root / as /dev/sda1 :-) and
> > I assume that the ttylinux file rootfs.gz has the same root device
> > "/dev/sda1" (... you can't change it anyway)
> >
> > ciao
> >
> > On 6/14/05, David_Schmidt@dell.com <David_Schmidt@dell.com> wrote:
> > > It's possible that the fstab is incorrect inside your image. Make sure
> > > it is mounting / as /dev/sda1.
>
> No, this:
>
> > > "kernel panic - not syncing: VFS: Unable to mount root fs on
> > > unknown-block (8,1)"
>
> means that the kernel could not recognize /dev/sda1
>
> (8,1) comes from the major and minor numbers, e.g. :
>
> [root@am3 ~]# ls -ld /dev/sda1
> brw-rw---- 1 root disk 8, 1 Mar 23 2001 /dev/sda1
>
> this would _not_ be an fstab issue, as the boot process has not
> gotten that far yet.
>
>
> > > disk = ['file:/home/name/vm1disk,sda1,w']
> > > root = "/dev/sda1"
>
> are you _sure_ that "/home/name/vm1disk" is correct? and can you
> mount it via loopback (my apologies if this has been covered).
>
> "name" seems pretty generic, I suspect you haven't changed it to
> your userid, or updated it for the path on your system?
>
> "unknown-block" sounds bad... like it isn't there, as compared to
> being misformatted or the like.
>
> -Tom
>
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>
--
Regards,

David F Barrera
Linux Technology Center
Systems and Technology Group, IBM

"The wisest men follow their own direction. "
Euripides

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Re: Suse 9.3 "kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block (8, 1)" [ In reply to ]

tbrown at baremetal

Jun 14, 2005, 2:05 PM

Post #5 of 7 (1167 views)

Permalink

On Tue, 14 Jun 2005, David F Barrera wrote:

> > > disk = ['file:/home/name/vm1disk,sda1,w']
> Try using '0801' instead of sda1

why? The kernel went to the right spot (8,1)...

> > > > "kernel panic - not syncing: VFS: Unable to mount root fs on
> > > > unknown-block (8,1)"

there just wasn't anything there... which suggests /home/name/vm1disk is
somehow not correct.

hhmm, I must be wrong. 2.0.5 won't let you specify an non existant file.

[root@xen1 /etc/xen]# xm create bogus -c
Using config file "bogus".
Error: Error creating domain: vbd: Segment not found: \
uname=file:/home/name/vm1disk

ok, if I create a bogus file, e.g. not a legit filesystem, I get

Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(8,1)

if I now turn around and format that bogus file as a filesystem,
e.g. mke2fs /tmp/delete.me and boot with

disk = [ 'file:/tmp/delete.me,sda1,w']

I get past that stage, and instead run into the more normal:

Warning: unable to open an initial console.
Kernel panic - not syncing: No init found. Try passing init=
option to kernel.

The warning indicates there was no /dev/console, and the "no
init" means that there was no /sbin/init program on the
filesystem (no suprise, it was just built for testing, so it was empty).

Anyhow, to cut a long story short...
/home/name/vm1disk file does exist, but apparently is not a valid
filesystem. And that is likely to take more than a few sentences to
explain away :-(

-Tom

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Re: Suse 9.3 "kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block (8, 1)" [ In reply to ]

james at xensource

Jun 14, 2005, 4:05 PM

Post #6 of 7 (1165 views)

Permalink

Tom Brown wrote:
> Anyhow, to cut a long story short...
> /home/name/vm1disk file does exist, but apparently is not a valid
> filesystem. And that is likely to take more than a few sentences to
> explain away :-(

It looks like the loopback mounting of this file may be failing, have a
look in xend-debug.log.

Is /home/name NFS mounted? If so, it might be exported with root squash
which will cause problems. See if you can loopback mount vm1disk. Try
copying vm1disk to /tmp and see if you can get the VM to start with
file:/tmp/vm1disk.

James

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Re: Suse 9.3 "kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block (8, 1)" [ In reply to ]

ervin23 at gmail

Jun 16, 2005, 8:51 AM

Post #7 of 7 (1172 views)

Permalink

thanks to all of you / the combined ideas you gave me did the trick
... I have several domins running now!

Next step is to get the network up to speed and the graphical
interface in place /

Have fun /

On 6/14/05, Tom Brown <tbrown@baremetal.com> wrote:
> On Tue, 14 Jun 2005, David F Barrera wrote:
>
> > > > disk = ['file:/home/name/vm1disk,sda1,w']
> > Try using '0801' instead of sda1
>
> why? The kernel went to the right spot (8,1)...
>
> > > > > "kernel panic - not syncing: VFS: Unable to mount root fs on
> > > > > unknown-block (8,1)"
>
> there just wasn't anything there... which suggests /home/name/vm1disk is
> somehow not correct.
>
> hhmm, I must be wrong. 2.0.5 won't let you specify an non existant file.
>
> [root@xen1 /etc/xen]# xm create bogus -c
> Using config file "bogus".
> Error: Error creating domain: vbd: Segment not found: \
> uname=file:/home/name/vm1disk
>
> ok, if I create a bogus file, e.g. not a legit filesystem, I get
>
> Kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block(8,1)
>
> if I now turn around and format that bogus file as a filesystem,
> e.g. mke2fs /tmp/delete.me and boot with
>
> disk = [ 'file:/tmp/delete.me,sda1,w']
>
> I get past that stage, and instead run into the more normal:
>
> Warning: unable to open an initial console.
> Kernel panic - not syncing: No init found. Try passing init=
> option to kernel.
>
> The warning indicates there was no /dev/console, and the "no
> init" means that there was no /sbin/init program on the
> filesystem (no suprise, it was just built for testing, so it was empty).
>
> Anyhow, to cut a long story short...
> /home/name/vm1disk file does exist, but apparently is not a valid
> filesystem. And that is likely to take more than a few sentences to
> explain away :-(
>
> -Tom
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>

--

mvh/best regards ervin

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