Re: [Xen-users] Xen DomU Communication Problems

Sarah Scheibe
2008-02-19T16:56:35Z

Thank you, that helped at least part of the problem.
I no longer get an error message when trying to create the domU, and it
appears that the device is getting passed in. However, dmesg on the domU
gives me

"PCI: Enabling device 0000:00:00.0 (0000 -> 0003)
scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 7.0
         <Adaptec 29160 Ultra160 SCSI adapter>
         aic7892: Ultra160 Wide Channel A, SCSI Id=7, 32/253 SCBs

Unable to handle kernel NULL pointer dereference at 0000000000000078 RIP:
  [<ffffffff880043a2>] :scsi_mod:scsi_calculate_bounce_limit+0x15/0x49
PGD 20750067 PUD 20751067 PMD 0
Oops: 0000 [1] SMP
CPU 0
Modules linked in: aic7xxx scsi_transport_spi scsi_mod
Pid: 510, comm: modprobe Not tainted 2.6.18-6-xen-amd64 #1
RIP: e030:[<ffffffff880043a2>]  [<ffffffff880043a2>]
:scsi_mod:scsi_calculate_bounce_limit+0x15/0x49"

.... followed by a call trace, etc. The device does not show up in /dev.

I will keep at it.

~Sarah

Todd Deshane wrote:
>
> Hi,
>
> On Feb 19, 2008 11:03 AM, Sarah Scheibe <scheibe@gfdi.fsu.edu
> <mailto:scheibe@gfdi.fsu.edu>> wrote:
>
>     Hi Again,
>
>     I have been attempting to pass the tape drive through to my domU, but
am
>     having no luck. I added pciback.hide(03:02.0) to my modules line in
>     menu.lst, and added "pci = [ ''03:02.0'' ].
I''ve rebooted the dom0,
>     and now
>     when I try to start the domU I get the following message:
>
>
>
> I think you have to fix your pciback.hide line to be:
>
> pciback.hde=(03:02.0)
>
> You may also want to add pciback.permissive to that line.
>
> Todd
>
>
>
>     "Error: pci: PCI Backend does not own device 0000:03:02.0
>     See the pciback.hide kernel command-line parameter or
>     bind your slot/device to the PCI backend using sysfs"
>
>     Any hints would be appreciated.
>
>     Thanks!
>     Sarah
>
>     Sarah Scheibe wrote:
>      > Stephan,
>      >
>      > Thank you for your response.
>      >
>      > I agree that the ideal solution is to get the tape drive to the
domU.
>      > However, I''ve tried pci passthrough in the past several
times and
>     so far
>      > have had absolutely no luck. I''m very open to
suggestions as to how I
>      > can make this tape drive accessible to the domU.
>      >
>      > ~Sarah
>      >
>      > Stephan Seitz wrote:
>      >>> Good Morning,
>      >> Depends ;)
>      >>
>      >>
>      >>> I have a Xen machine with a domU that provides backups
for our
>      >>> department. The domU is running Bacula. The dom0 hosts
the bacula
>      >>> storage daemon which communicates with the tape device
connected to
>      >>> the dom0.
>      >>>
>      >>> I recently moved our file server onto this machine under
this dom0.
>      >>> Prior to this move, backups worked fine on the file
server as
>     well as
>      >>> everything else. However, post move, whenever I attempt
to back up
>      >>> the file server I lose network on both domUs (the backup
server and
>      >>> the file server) until I either kill the bacula storage
daemon
>     on the
>      >>> dom0 or console in to the backup server and kill bacula
from there.
>      >>> After that, networking returns to both domUs immediately.
>      >>
>      >> I''ve always noticed problems when using
load-intensive apps directly
>      >> on dom0.
>      >>
>      >> If you''re lucky, you''ve got enough cores
and could try to
>     cpu-pin dom0
>      >> and
>      >> domU''s to different, dedicated cores. If your
domU''s are HVM,
>     you should
>      >> check if the netfront modules are loaded and used.
>      >> Anyway, I would prefer to look on how to get the tape drive
>     available in
>      >> your bacula domU and leave dom0 for managing stuff.
>      >>
>      >>
>      >>> These two domUs are the only domUs on this machine.
Networking is
>      >>> never affected on the dom0, just the domUs. Backing up
all other
>      >>> servers still works just fine.
>      >>>
>      >>> I am frankly stumped. I am running a debian distribution,
and have
>      >>> tried upgrading the kernel to version 2.6.18 and
upgrading to the
>      >>> most recent Xen hypervisor *MailScanner warning:
numerical
>     links are often malicious:* 3.0.3.1 <http://3.0.3.1> revision,
all
>     without luck in
>      >>> solving the problem.
>      >>>
>      >>> If anyone has any ideas or has run into this problem and
found a
>      >>> solution, your advice would be greatly appreciated.
>      >>>
>      >>> Sincerely,
>      >>> Sarah
>      >>>
>      >>> _______________________________________________
>      >>> Xen-users mailing list
>      >>> Xen-users@lists.xensource.com
>     <mailto:Xen-users@lists.xensource.com>
>      >>> http://lists.xensource.com/xen-users
>      >>
>      >>
>      >
>
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