Xen devel - Dec 2004 - failed startup caused by unpriveledged domain device nodes not present in priviledged domain

I have a gentoo install running as Domain0 which uses a compaq smart 
array for it''s disk storage (/dev/ida/c0d0) because of this, there are 
no device nodes present for /dev/sdX or /dev/hdX (aside from /dev/hdc 
for the cdrom). I''m trying to make my unpriviledged domains use lvm 
volumes with the following configuration:

disk = [ ''phy:fs/ns1,sda1,w'',
''phy:fs/ns1_swap,sda2,w'' ]

When I try and start the domain, I get the following output:

Using config file "/etc/xen/ns1".
Error: Error creating domain: vbd: Device not found: sda1

If I replace sda1 with hdc it works (except that it now complains about 
sda2).

This strikes me as odd behaviour, shouldn''t the device nodes in the 
priviledged domains be largely irrelevant for the unpriviledged domains 
(in the case of vbds at any rate)?

Thanks in advance,
Scott.


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. 
http://productguide.itmanagersjournal.com/
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/xen-devel

On Thu, Dec 23, 2004 at 01:37:08AM +1300, Scott Mohekey
wrote:
> I have a gentoo install running as Domain0 which uses a compaq smart 
> array for it''s disk storage (/dev/ida/c0d0) because of this, there
are
> no device nodes present for /dev/sdX or /dev/hdX (aside from /dev/hdc 
> for the cdrom). I''m trying to make my unpriviledged domains use
lvm
> volumes with the following configuration:
> 
> disk = [ ''phy:fs/ns1,sda1,w'',
''phy:fs/ns1_swap,sda2,w'' ]
> 
> When I try and start the domain, I get the following output:
> 
> Using config file "/etc/xen/ns1".
> Error: Error creating domain: vbd: Device not found: sda1
> 
> If I replace sda1 with hdc it works (except that it now complains about 
> sda2).
IIRC, I had the same problem with a FC3 because of udev and no /dev/sd*
devices in the domain0.

You can either create the devices manually (cd /dev && MAKEDEV sda), or
use hda1, hda2 instead of sda1, sda2.
> This strikes me as odd behaviour, shouldn''t the device nodes in
the
> priviledged domains be largely irrelevant for the unpriviledged domains 
> (in the case of vbds at any rate)?
Yes, but xen probably needs those in order to find out the major and
minor information.

It would be nice if xen was changed to try some defaults for sd and hd,
though.

Regards,
Luciano Rocha


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. 
http://productguide.itmanagersjournal.com/
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/xen-devel

> Using config file "/etc/xen/ns1".
> Error: Error creating domain: vbd: Device not found: sda1
Xend uses the local device nodes in domain zero to look up the major / minor 
numbers for a virtual device before creating it.

On udev / devfs dom0s this problem does crop up, so it''s also possible
to
specify the the device node number manually: try replacing sda1 with 0801.

Cheers,
Mark
> If I replace sda1 with hdc it works (except that it now complains about
> sda2).
>
> This strikes me as odd behaviour, shouldn''t the device nodes in
the
> priviledged domains be largely irrelevant for the unpriviledged domains
> (in the case of vbds at any rate)?
>
> Thanks in advance,
> Scott.
>
>
> -------------------------------------------------------
> SF email is sponsored by - The IT Product Guide
> Read honest & candid reviews on hundreds of IT Products from real
users.
> Discover which products truly live up to the hype. Start reading now.
> http://productguide.itmanagersjournal.com/
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/xen-devel

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. 
http://productguide.itmanagersjournal.com/
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/xen-devel

> > disk = [ ''phy:fs/ns1,sda1,w'',
''phy:fs/ns1_swap,sda2,w'' ]
> > 
> > When I try and start the domain, I get the following output:
> > 
> > Using config file "/etc/xen/ns1".
> > Error: Error creating domain: vbd: Device not found: sda1
> > 
> > If I replace sda1 with hdc it works (except that it now complains 
> > about sda2).
> 
> IIRC, I had the same problem with a FC3 because of udev and 
> no /dev/sd* devices in the domain0.
> 
> You can either create the devices manually (cd /dev && 
> MAKEDEV sda), or use hda1, hda2 instead of sda1, sda2.
Or, use the numeric form of sda1 ''0801''.
> > This strikes me as odd behaviour, shouldn''t the device nodes
in the
> > priviledged domains be largely irrelevant for the unpriviledged 
> > domains (in the case of vbds at any rate)?
> 
> Yes, but xen probably needs those in order to find out the 
> major and minor information.
> 
> It would be nice if xen was changed to try some defaults for 
> sd and hd, though.
Yes, we should do this. Patches gratefuly accepted ;-)

Ian


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. 
http://productguide.itmanagersjournal.com/
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/xen-devel

Thanks, using the number manually worked perfectly. However, now I''m 
back to the original error I was having in another post:

Using config file "/etc/xen/ns1".
Error: Error creating domain: vbd: Segment not found: uname=phy:fs/ns1

This is after entering:
xm create ns1 -c

Thanks for your time.
Scott.

Mark Williamson wrote:
>>Using config file "/etc/xen/ns1".
>>Error: Error creating domain: vbd: Device not found: sda1
>>    
>>
>
>Xend uses the local device nodes in domain zero to look up the major / minor
>numbers for a virtual device before creating it.
>
>On udev / devfs dom0s this problem does crop up, so it''s also
possible to
>specify the the device node number manually: try replacing sda1 with 0801.
>
>Cheers,
>Mark
>
>  
>
>>If I replace sda1 with hdc it works (except that it now complains about
>>sda2).
>>
>>This strikes me as odd behaviour, shouldn''t the device nodes in
the
>>priviledged domains be largely irrelevant for the unpriviledged domains
>>(in the case of vbds at any rate)?
>>
>>Thanks in advance,
>>Scott.
>>
>>
>>-------------------------------------------------------
>>SF email is sponsored by - The IT Product Guide
>>Read honest & candid reviews on hundreds of IT Products from real
users.
>>Discover which products truly live up to the hype. Start reading now.
>>http://productguide.itmanagersjournal.com/
>>_______________________________________________
>>Xen-devel mailing list
>>Xen-devel@lists.sourceforge.net
>>https://lists.sourceforge.net/lists/listinfo/xen-devel
>>    
>>
>
>
>-------------------------------------------------------
>SF email is sponsored by - The IT Product Guide
>Read honest & candid reviews on hundreds of IT Products from real users.
>Discover which products truly live up to the hype. Start reading now. 
>http://productguide.itmanagersjournal.com/
>_______________________________________________
>Xen-devel mailing list
>Xen-devel@lists.sourceforge.net
>https://lists.sourceforge.net/lists/listinfo/xen-devel
>
>  
>


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. 
http://productguide.itmanagersjournal.com/
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/xen-devel