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<ramamurthy.suresh@wipro.com>

2008-Jun-10 14:11 UTC

[Xen-users] Reg:Error: VFS: Cannot open root device.

Hi all,

 

I''m trying to bring up a guest OS on Linux with Xen. I have booted the
PC with Dom 0 in the partition /dev/hdc2 (Size 10 GB).  

 

I have created a separate partition /dev/hdc3 (size 10 GB) and
replicated the Dom 0 directories in this partition and changed the
/etc/fstab in /dev/hda3 (/mnt - have mounted this partition (/dev/hdc3)
in /mnt ) as 

 

/dev/sda1            /                       ext3    defaults       1 1
(sda1 -> because have specified this in the guest os configuration file)

 

I have unmounted /dev/hdc3 (/mnt) before booting the guest OS. ( ! )

 

The Guest OS configuration file looks like 

 

kernel = "/boot/vmlinuz-2.6.18-53.el5xen" - this image in same as Dom
0.

memory = 64

vif = [ '''' ]

disk = [ ''phy:hdc3,sda1,w'' ]

root = "/dev/sda1 ro"

extra = "4 debug"

 

When I ran this configuration file for booting guest OS using - xm
create myvmconf vmid=1, I''m getting the following errors:

 

XENBUS: Device with no driver: device/vbd/257

XENBUS: Device with no driver: device/vif/0

md: Autodetecting RAID arrays.

md: autorun ...

md: ... autorun DONE.

VFS: Cannot open root device "sda1" 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)

 

The Xend log shows

 

[2008-06-10 19:22:17 xend 2404] INFO (image:136) buildDomain os=linux
dom=95 vcpus=1

[2008-06-10 19:22:17 xend 2404] DEBUG (image:201) domid          = 95

[2008-06-10 19:22:17 xend 2404] DEBUG (image:202) memsize        = 64

[2008-06-10 19:22:17 xend 2404] DEBUG (image:203) image         
/boot/vmlinuz-2.6.18-53.el5xen

[2008-06-10 19:22:17 xend 2404] DEBUG (image:204) store_evtchn   = 1

[2008-06-10 19:22:17 xend 2404] DEBUG (image:205) console_evtchn = 2

[2008-06-10 19:22:17 xend 2404] DEBUG (image:206) cmdline        root=/dev/sda1
ro 4 debug

[2008-06-10 19:22:17 xend 2404] DEBUG (image:207) ramdisk        
[2008-06-10 19:22:17 xend 2404] DEBUG (image:208) vcpus          = 1

[2008-06-10 19:22:17 xend 2404] DEBUG (image:209) features       
[2008-06-10 19:22:17 xend 2404] DEBUG (DevController:110) DevController:
writing {''virtual-device'': ''257'',
''device-type'': ''disk'',
''protocol'':
''x86_32-abi'', ''backend-id'':
''0'', ''state'': ''1'',
''backend'':
''/local/domain/0/backend/vbd/95/257''} to
/local/domain/95/device/vbd/257.

[2008-06-10 19:22:17 xend 2404] DEBUG (DevController:112) DevController:
writing {''domain'': ''VirtualMachine1'',
''frontend'':
''/local/domain/95/device/vbd/257'', ''dev'':
''sda1'', ''state'': ''1'',
''params'': ''hdc3'', ''mode'':
''w'', ''online'': ''1'',
''frontend-id'': ''95'',
''type'': ''phy''} to
/local/domain/0/backend/vbd/95/257.

[2008-06-10 19:22:17 xend 2404] DEBUG (DevController:110) DevController:
writing {''mac'': ''00:16:3e:5b:c1:84'',
''handle'': ''0'', ''protocol'':
''x86_32-abi'', ''backend-id'':
''0'', ''state'': ''1'',
''backend'':
''/local/domain/0/backend/vif/95/0''} to
/local/domain/95/device/vif/0.

[2008-06-10 19:22:17 xend 2404] DEBUG (DevController:112) DevController:
writing {''domain'': ''VirtualMachine1'',
''handle'': ''0'', ''script'':
''/etc/xen/scripts/vif-bridge'', ''state'':
''1'', ''frontend'':
''/local/domain/95/device/vif/0'', ''mac'':
''00:16:3e:5b:c1:84'', ''online'':
''1'', ''frontend-id'': ''95''}
to /local/domain/0/backend/vif/95/0.

[2008-06-10 19:22:17 xend.XendDomainInfo 2404] DEBUG
(XendDomainInfo:756) Storing VM details: {''shadow_memory'':
''0'', ''uuid'':
''6cfaa5d1-5a71-09b4-a888-39912a79565f'',
''on_reboot'': ''restart'',
''start_time'': ''1213105937.65'',
''on_poweroff'': ''destroy'',
''name'':
''VirtualMachine1'', ''xend/restart_count'':
''0'', ''vcpus'': ''1'',
''vcpu_avail'': ''1'',
''memory'': ''64'',
''on_crash'': ''destroy'',
''image'':
"(linux (kernel /boot/vmlinuz-2.6.18-53.el5xen) (root ''/dev/sda1
ro'')
(args ''4 debug''))", ''maxmem'':
''64''}

[2008-06-10 19:22:17 xend.XendDomainInfo 2404] DEBUG
(XendDomainInfo:791) Storing domain details:
{''console/ring-ref'':
''100635'', ''console/port'':
''2'', ''name'':
''VirtualMachine1'',
''console/limit'': ''1048576'',
''vm'':
''/vm/6cfaa5d1-5a71-09b4-a888-39912a79565f'',
''domid'': ''95'',
''cpu/0/availability'': ''online'',
''memory/target'': ''65536'',
''store/ring-ref'': ''100636'',
''store/port'': ''1''}

[2008-06-10 19:22:17 xend.XendDomainInfo 2404] DEBUG
(XendDomainInfo:988) XendDomainInfo.handleShutdownWatch

[2008-06-10 19:22:17 xend 2404] DEBUG (DevController:143) Waiting for
devices vif.

[2008-06-10 19:22:17 xend 2404] DEBUG (DevController:149) Waiting for 0.

[2008-06-10 19:22:17 xend 2404] DEBUG (DevController:476)
hotplugStatusCallback /local/domain/0/backend/vif/95/0/hotplug-status.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:476)
hotplugStatusCallback /local/domain/0/backend/vif/95/0/hotplug-status.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:490)
hotplugStatusCallback 1.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices usb.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices vbd.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:149) Waiting for
257.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:476)
hotplugStatusCallback /local/domain/0/backend/vbd/95/257/hotplug-status.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:490)
hotplugStatusCallback 1.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices irq.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices vkbd.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices vfb.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices pci.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices ioports.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices tap.

[2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
devices vtpm.

[2008-06-10 19:22:19 xend 2404] INFO (XendDomain:370) Domain
VirtualMachine1 (95) unpaused. 

[2008-06-10 19:22:23 xend.XendDomainInfo 2404] WARNING
(XendDomainInfo:923) Domain has crashed: name=VirtualMachine1 id=95.

/* There is no reason being displaced for crashing this daemon */

[2008-06-10 19:22:23 xend.XendDomainInfo 2404] DEBUG
(XendDomainInfo:1557) XendDomainInfo.destroy: domid=95

[2008-06-10 19:22:23 xend.XendDomainInfo 2404] DEBUG
(XendDomainInfo:1566) XendDomainInfo.destroyDomain(95)

[2008-06-10 19:22:24 xend 2404] DEBUG (DevController:476)
hotplugStatusCallback /local/domain/0/backend/vbd/1/2049/hotplug-status.

 

Please help me getting through this. Any help is appreciated. Thanks in
advance.

 

Thanks

-Suresh.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


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Todd Deshane

2008-Jun-10 22:19 UTC

head link

Re: [Xen-users] Reg:Error: VFS: Cannot open root device.

On Tue, Jun 10, 2008 at 10:11 AM, <ramamurthy.suresh@wipro.com> wrote:
>  Hi all,
>
>
>
> I''m trying to bring up a guest OS on Linux with Xen. I have booted
the PC
> with Dom 0 in the partition /dev/hdc2 (Size 10 GB).
>
>
>
> I have created a separate partition /dev/hdc3 (size 10 GB) and replicated
> the Dom 0 directories in this partition and changed the /etc/fstab in
> /dev/hda3 (/mnt - have mounted this partition (/dev/hdc3) in /mnt ) as
>
>
>
> /dev/sda1            /                       ext3    defaults       1 1
> (sda1 -> because have specified this in the guest os configuration file)
>
>
>
> I have unmounted /dev/hdc3 (/mnt) before booting the guest OS. ( ! )
>
>
>
> The Guest OS configuration file looks like
>
>
>
> kernel = "/boot/vmlinuz-2.6.18-53.el5xen" – this image in same as
Dom 0.
>
> memory = 64
>
> vif = [ '''' ]
>
> disk = [ ''phy:hdc3,sda1,w'' ]
>
> root = "/dev/sda1 ro"
>
> extra = "4 debug"
>
>
>
> When I ran this configuration file for booting guest OS using - xm create
> myvmconf vmid=1, I''m getting the following errors:
>
>
>
> XENBUS: Device with no driver: device/vbd/257
>
> XENBUS: Device with no driver: device/vif/0
>
> md: Autodetecting RAID arrays.
>
> md: autorun ...**
>
> md: ... autorun DONE.
>
> *VFS: Cannot open root device "sda1" 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)*
>
> * *
>
> The Xend log shows
>
>
>
> [2008-06-10 19:22:17 xend 2404] INFO (image:136) buildDomain os=linux
> dom=95 vcpus=1
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:201) domid          = 95
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:202) memsize        = 64
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:203) image          = *
> /boot/vmlinuz-2.6.18-53.el5xen*
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:204) store_evtchn   = 1
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:205) console_evtchn = 2
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:206) cmdline        >
root=/dev/sda1 ro 4 debug
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:207) ramdisk        >
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:208) vcpus          = 1
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (image:209) features       >
> [2008-06-10 19:22:17 xend 2404] DEBUG (DevController:110) DevController:
> writing {''virtual-device'': ''257'',
''device-type'': ''disk'',
''protocol'':
> ''x86_32-abi'', ''backend-id'':
''0'', ''state'': ''1'',
''backend'':
> ''/local/domain/0/backend/vbd/95/257''} to
/local/domain/95/device/vbd/257.
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (DevController:112) DevController:
> writing {''domain'': ''VirtualMachine1'',
''frontend'':
> ''/local/domain/95/device/vbd/257'',
''dev'': ''sda1'', ''state'':
''1'', ''params'':
> ''hdc3'', ''mode'': ''w'',
''online'': ''1'',
''frontend-id'': ''95'',
''type'': ''phy''} to
> /local/domain/0/backend/vbd/95/257.
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (DevController:110) DevController:
> writing {''mac'': ''00:16:3e:5b:c1:84'',
''handle'': ''0'', ''protocol'':
> ''x86_32-abi'', ''backend-id'':
''0'', ''state'': ''1'',
''backend'':
> ''/local/domain/0/backend/vif/95/0''} to
/local/domain/95/device/vif/0.
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (DevController:112) DevController:
> writing {''domain'': ''VirtualMachine1'',
''handle'': ''0'', ''script'':
> ''/etc/xen/scripts/vif-bridge'', ''state'':
''1'', ''frontend'':
> ''/local/domain/95/device/vif/0'', ''mac'':
''00:16:3e:5b:c1:84'', ''online'':
''1'',
> ''frontend-id'': ''95''} to
/local/domain/0/backend/vif/95/0.
>
> [2008-06-10 19:22:17 xend.XendDomainInfo 2404] DEBUG (XendDomainInfo:756)
> Storing VM details: {''shadow_memory'':
''0'', ''uuid'':
> ''6cfaa5d1-5a71-09b4-a888-39912a79565f'',
''on_reboot'': ''restart'',
> ''start_time'': ''1213105937.65'',
''on_poweroff'': ''destroy'',
''name'':
> ''VirtualMachine1'',
''xend/restart_count'': ''0'',
''vcpus'': ''1'',
''vcpu_avail'':
> ''1'', ''memory'': ''64'',
''on_crash'': ''destroy'',
''image'': "(linux (kernel
> /boot/vmlinuz-2.6.18-53.el5xen) (root ''/dev/sda1 ro'')
(args ''4 debug''))",
> ''maxmem'': ''64''}
>
> [2008-06-10 19:22:17 xend.XendDomainInfo 2404] DEBUG (XendDomainInfo:791)
> Storing domain details: {''console/ring-ref'':
''100635'', ''console/port'':
''2'',
> ''name'': ''VirtualMachine1'',
''console/limit'': ''1048576'',
''vm'':
> ''/vm/6cfaa5d1-5a71-09b4-a888-39912a79565f'',
''domid'': ''95'',
> ''cpu/0/availability'': ''online'',
''memory/target'': ''65536'',
''store/ring-ref'':
> ''100636'', ''store/port'':
''1''}
>
> [2008-06-10 19:22:17 xend.XendDomainInfo 2404] DEBUG (XendDomainInfo:988)
> XendDomainInfo.handleShutdownWatch
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (DevController:143) Waiting for
> devices vif.
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (DevController:149) Waiting for 0.
>
> [2008-06-10 19:22:17 xend 2404] DEBUG (DevController:476)
> hotplugStatusCallback /local/domain/0/backend/vif/95/0/hotplug-status.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:476)
> hotplugStatusCallback /local/domain/0/backend/vif/95/0/hotplug-status.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:490)
> hotplugStatusCallback 1.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices usb.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices vbd.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:149) Waiting for 257.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:476)
> hotplugStatusCallback /local/domain/0/backend/vbd/95/257/hotplug-status.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:490)
> hotplugStatusCallback 1.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices irq.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices vkbd.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices vfb.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices pci.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices ioports.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices tap.
>
> [2008-06-10 19:22:19 xend 2404] DEBUG (DevController:143) Waiting for
> devices vtpm.
>
> [2008-06-10 19:22:19 xend 2404] INFO (XendDomain:370) *Domain
> VirtualMachine1 (95) unpaused. *
>
> *[2008-06-10 19:22:23 xend.XendDomainInfo 2404] WARNING
> (XendDomainInfo:923) Domain has crashed: name=VirtualMachine1 id=95.*
>
> */* There is no reason being displaced for crashing this daemon */*
>
> [2008-06-10 19:22:23 xend.XendDomainInfo 2404] DEBUG (XendDomainInfo:1557)
> XendDomainInfo.destroy: domid=95
>
> [2008-06-10 19:22:23 xend.XendDomainInfo 2404] DEBUG (XendDomainInfo:1566)
> XendDomainInfo.destroyDomain(95)
>
> [2008-06-10 19:22:24 xend 2404] DEBUG (DevController:476)
> hotplugStatusCallback /local/domain/0/backend/vbd/1/2049/hotplug-status.
>
>
>
> Please help me getting through this. Any help is appreciated. Thanks in
> advance.
>
Looks like you are probably just missing the scsi module for the domU.

You should add a ramdisk= line to your guest config, that should fix the
problem provided that the initrd that you pass has the module, otherwise add
the module
to it and boot with the updated ramdisk file.


Cheers,
Todd


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Xen users - Jun 2008 - Reg:Error: VFS: Cannot open root device.

[Xen-users] Reg:Error: VFS: Cannot open root device.

Re: [Xen-users] Reg:Error: VFS: Cannot open root device.