Re: Windows domu DRBD backend problem

[Kotán Attila <info@xxxxxxxx>]

Hello Tu Dinh,

I attached the file windbg_output.txt and xenstore_output.txt 
(xenstore-ls -fp command output).
The C: drive is:  /local/domain/0/backend/vbd/13/51712

I hope this is the info what you ask.

Thank you and Best Regards,
Attila



2025. 05. 09. 19:01 keltezéssel, Tu Dinh írta:
> Hi Attila,
>
> On 09/05/2025 11:55, Kotán Attila wrote:
> > Hello Tu Dinh,
> >
> > I created an debug environment for Qemu, but the Qemu debug not provide
> > any info after the XEn drivers loaded in windows.
> >
> > Then i make an windbg connection to Domu and try to DEbug with windbg.
> >
> > When the DRBD backend status is change the following DEBUG info coming
> > to windbg:
> >
> > -----
> > xenvbd|TargetReset:[0] =====>
> > xenvbd|__FrontendSetState:Target[0] : ENABLED ----> CONNECTED
> > xenvbd|__BlkifRingCompleteResponse:Target[0][0] : WRITE BLKIF_RSP_ERROR
> > xenvbd|__FrontendSetState:Target[0] : in state CONNECTED
> > xenvbd|__FrontendSetState:Target[0] : CONNECTED ----> ENABLED
> > xenvbd|__FrontendSetState:Target[0] : in state ENABLED
> > xenvbd|TargetReset:[0] <=====
> > xenvbd|__BlkifRingCompleteResponse:Target[0][0] : WRITE BLKIF_RSP_ERROR
> > Terminating critical process 0xFFFFD18EFF72A140 (services.exe)
> > -----
> >
> > It was a very difficult to make the Debug environment for me.
> >
> > I really don't understand why detecting the xenvbd driver the DRBD
> > status change.
> >
> > If you need more debug info, then please instruct me about how can i got
> > it from windbg.
> >
> > Thank you and best regards.
> >
> > Attila
> The Windows guest kernel log is what I was looking for. The
> xen_platform_log feature of QEMU should give you the same log as Windbg
> while being easier to set up.
>
>   From the log you posted, it looks like Windows tried to reset the
> virtual block device when an I/O failed during a failover, and this got
> stuck somewhere.
>
> Do you have the Windows kernel thread stack trace at the time of hang,
> as well as the VM and backend's Xenstore states? You can use
> `xenstore-ls` on the host, or force a BSOD with Windbg which will cause
> Xen drivers to spew this information onto xen_platform_log.
>
> Best regards,
>
>
>   | Vates
>
> XCP-ng & Xen Orchestra - Vates solutions
>
> web: https://vates.tech

Attachment: windbg_output.txt
Description: Text document

Attachment: xenstore_output.txt
Description: Text document