Automatically resync kernel connection

WINDBG
1

I have a test environment where tests are continuously pushed down to multiple VMs (the VMs reside on an ESX server), the test is run, and then each VM is automatically reverted so it can run another test. I need to catch all bug checks coming from the VMs, so I have an additional VM which has multiple instances of windbg running each connected to a separate com port. I have the VMs set to /debug=autoenable,noumex (/debugcrash for the xp/2k3 machines) to avoid catching usermode exceptions.

The problem I am having is the Vista and server 2k8 machines will sometimes freeze when starting a test, until I manual resync the kernel connection in windbg.

Is there a way to avoid this freeze, or to have windbg automatically resync the kernel connection?

2

What’s your windbg command line/how are you connecting?

In particular, are you specifying ‘resets’ and/or ‘reconnect?’

mm

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@sunbeltsoftware.com
Sent: Tuesday, April 05, 2011 9:30 AM
To: Kernel Debugging Interest List
Subject: [windbg] Automatically resync kernel connection

I have a test environment where tests are continuously pushed down to
multiple VMs (the VMs reside on an ESX server), the test is run, and then
each VM is automatically reverted so it can run another test. I need to
catch all bug checks coming from the VMs, so I have an additional VM which
has multiple instances of windbg running each connected to a separate com
port. I have the VMs set to /debug=autoenable,noumex (/debugcrash for the
xp/2k3 machines) to avoid catching usermode exceptions.

The problem I am having is the Vista and server 2k8 machines will sometimes
freeze when starting a test, until I manual resync the kernel connection in
windbg.

Is there a way to avoid this freeze, or to have windbg automatically resync
the kernel connection?

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3

I’m using the windbg gui to connect to the VMs. I have reconnect checked and resets set to 0.

Also don’t know if it will help, but baudrate is 115200 and pipe is not selected (its has to be a physical com port for esx).

4

Alas, I’ve never used ESX. I don’t have anything to offer.

Good luck,

mm

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@sunbeltsoftware.com
Sent: Tuesday, April 05, 2011 3:05 PM
To: Kernel Debugging Interest List
Subject: RE:[windbg] Automatically resync kernel connection

I’m using the windbg gui to connect to the VMs. I have reconnect checked and
resets set to 0.

Also don’t know if it will help, but baudrate is 115200 and pipe is not
selected (its has to be a physical com port for esx).

WINDBG is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at
http://www.osronline.com/page.cfm?name=ListServer

5

I don’t believe it’s directly related to ESX. So any ideas in general would be appreciated.

Is it possible to write a WinDbg extension that would resync every few seconds?

6

Just incase anyone else has this issue, I decided to just use an AutoIt script.

The script opens the windbg with the proper command line options, sleeps for a few seconds to let windbg launch. Then sends CTRL+ALT+R once a minute.

Run(‘“c:\program files\Debugging tools for windows (x86)\windbg.exe” -k com:port=com1,baud=115200,resets=0,reconnect’)

Sleep( 10000 )

While True
Send( “^!r” )
Sleep( 60000 )
WEnd