xen discuss - Jul 2008 - snv_91 dom0 and problems with the file:/ based storage in domUs

Hi all,

Quick one - is it a known problem on snv_91 that file:/ based disk devices
don''t work? Is there any other workaround than running
''lofiadm -a'' on the disk files and using phy:/dev/lofi/* in
the domU config files?

Regards,

Andrzej
 
 
This message posted from opensolaris.org

It should work.  What kind of problem did you see?

Max

Andrzej Szeszo wrote:
> Hi all,
>
> Quick one - is it a known problem on snv_91 that file:/ based disk devices
don''t work? Is there any other workaround than running
''lofiadm -a'' on the disk files and using phy:/dev/lofi/* in
the domU config files?
>
> Regards,
>
> Andrzej
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> xen-discuss mailing list
> xen-discuss@opensolaris.org
>

Yeah, it should work. It was working fine on snv_86 dom0.

This works:
# lofiadm 
Block Device             File                           Options
/dev/lofi/1              /export/disk.img               -
# cat /export/home/aszeszo/os
name = "opensolaris"
vcpus = 1
memory = "512"
#disk = [''file:/export/disk.img,0,w'']
disk = [''phy:/dev/lofi/1,0,w'']
vif = ['''']

It doesn''t work with the below:
# lofiadm 
Block Device             File                           Options
# cat /export/home/aszeszo/os
name = "opensolaris"
vcpus = 1
memory = "512"
disk = [''file:/export/disk.img,0,w'']
#disk = [''phy:/dev/lofi/1,0,w'']
vif = ['''']

I am seeing this message in the logs:
May  7 10:56:24 v-aszeszo xdb: [ID 269379 kern.warning] WARNING: xdb@6,0: Failed
to create lofi dev for /export/disk.img

I am seeing the same behaviour with other disk/iso images as well.

Regards,

Andrzej
 
 
This message posted from opensolaris.org

Andrzej Szeszo wrote:
> Yeah, it should work. It was working fine on snv_86 dom0.
>
> This works:
> # lofiadm 
> Block Device             File                           Options
> /dev/lofi/1              /export/disk.img               -
> # cat /export/home/aszeszo/os
> name = "opensolaris"
> vcpus = 1
> memory = "512"
> #disk = [''file:/export/disk.img,0,w'']
> disk = [''phy:/dev/lofi/1,0,w'']
> vif = ['''']
>
> It doesn''t work with the below:
> # lofiadm 
> Block Device             File                           Options
> # cat /export/home/aszeszo/os
> name = "opensolaris"
> vcpus = 1
> memory = "512"
> disk = [''file:/export/disk.img,0,w'']
> #disk = [''phy:/dev/lofi/1,0,w'']
> vif = ['''']
>
> I am seeing this message in the logs:
> May  7 10:56:24 v-aszeszo xdb: [ID 269379 kern.warning] WARNING: xdb@6,0:
Failed to create lofi dev for /export/disk.img
>   
Hmm...xdb will call lofi_ioctl() to create the lofi device. So, 
lofi_ioctl() could be failing...
Could you run below dtrace command to find out what is the return value 
of lofi_ioctl():
#dtrace -n fbt:lofi:lofi_ioctl:return''{trace(arg1)}''
You need to first run above command, then start your domain.

Thanks,
Max
> I am seeing the same behaviour with other disk/iso images as well.
>
> Regards,
>
> Andrzej
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> xen-discuss mailing list
> xen-discuss@opensolaris.org
>

This is what see after starting the domU:

[root@xvm0 ~]# dtrace -n
fbt:lofi:lofi_ioctl:return''{trace(arg1)}''
dtrace: description ''fbt:lofi:lofi_ioctl:return'' matched 1
probe
CPU     ID                    FUNCTION:NAME
  0  49267                lofi_ioctl:return                22


Thanks,

Andrzej
 
 
This message posted from opensolaris.org

Andrzej Szeszo wrote:
> This is what see after starting the domU:
>
> [root@xvm0 ~]# dtrace -n
fbt:lofi:lofi_ioctl:return''{trace(arg1)}''
> dtrace: description ''fbt:lofi:lofi_ioctl:return'' matched
1 probe
> CPU     ID                    FUNCTION:NAME
>   0  49267                lofi_ioctl:return                22
>   
OK, lofi_ioctl did fail with EINVAL(22).  Then, let''s probe a little
bit
more.
Please run below dtrace script and send out the output:
-------------------------------
#! /usr/sbin/dtrace -Fs

fbt:lofi:lofi_ioctl:entry
{
        self->mark = 1;
}
fbt:lofi:lofi_ioctl:return
{
        self->mark = 0;
        exit(0);
}
fbt:lofi::entry
/ self->mark == 1 /
{
}
fbt:lofi::return
/ self->mark == 1 /
{
        trace(arg1);
}
-------------------------------
Again, you need to start this script first, then try to create your domU.

Thanks,
Max
>
> Thanks,
>
> Andrzej
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> xen-discuss mailing list
> xen-discuss@opensolaris.org
>

Here is the output:

-bash-3.2# ./aa.d 
dtrace: script ''./aa.d'' matched 100 probes
CPU FUNCTION                                 
  0  -> lofi_ioctl                            
  0    -> lofi_map_file                       
  0      -> copy_in_lofi_ioctl                
  0      <- copy_in_lofi_ioctl                       3698379008
  0      -> valid_filename                    
  0      <- valid_filename                                    0
  0      -> free_lofi_ioctl                   
  0      <- free_lofi_ioctl                               94347
  0    <- lofi_map_file                                      22
  0  <- lofi_ioctl                            

The file I''m trying to use as a disk image is stored on the local ZFS
filesystem at /export/disk.img.

Regards,

Andrzej
 
 
This message posted from opensolaris.org

On Mon, Jul 07, 2008 at 07:17:26AM -0700, Andrzej Szeszo wrote:
> -bash-3.2# ./aa.d 
> dtrace: script ''./aa.d'' matched 100 probes
> CPU FUNCTION                                 
>   0  -> lofi_ioctl                            
>   0    -> lofi_map_file                       
>   0      -> copy_in_lofi_ioctl                
>   0      <- copy_in_lofi_ioctl                       3698379008
>   0      -> valid_filename                    
>   0      <- valid_filename                                    0
>   0      -> free_lofi_ioctl                   
>   0      <- free_lofi_ioctl                               94347
>   0    <- lofi_map_file                                      22
>   0  <- lofi_ioctl                            
> 
> The file I''m trying to use as a disk image is stored on the local
ZFS filesystem at /export/disk.img.
My crystal ball tells me you''re using OpenSolaris. It''s
shipping a
version of the lofi driver that isn''t updated correctly (I thought that
was an internal problem only, but apparently not). If you download SXCE
and replace /kernel/drv/[amd64/]/lofi from that media, it should work

Can you file a bug on defect.opensolaris.org?

regards
john

Hi John,

Your crystal ball is right. I''m using OpenSolaris. I always though that
the bits in SXCE and OpenSolaris were the same and the difference was only in
the packaging.

file:/ backed disks work just fine with the lofi driver from SXCE.

I''ll file a bug soon.

Thanks a lot!

Andrzej
 
 
This message posted from opensolaris.org

On Mon, Jul 07, 2008 at 09:14:18AM -0700, Andrzej Szeszo wrote:
> Your crystal ball is right. I''m using OpenSolaris. I always though
> that the bits in SXCE and OpenSolaris were the same and the difference
> was only in the packaging.
This is in fact mostly the case. However, OpenSolaris has some
customisations. lofi was one of the original ones so they could do
compressed lofi. That''s in Nevada now, so it''s not really
necessary for
them to use their own version, so I think it''s an oversight.

regards,
john

I had the same issue.

To anyone else facing this and not having a running SXCE install close by,
download the first CD of SXCE snv_93 and loopback mount the iso.
Then you can copy the lofi driver from <iso
mnt>/Product/SUNWckr/reloc/kernel/drv/amd64/lofi.

HTH,
Greg.
 
 
This message posted from opensolaris.org