How to Debug Windows Memory Dumps

Monday, May 14, 2007

From time to time, we're faced with the dreaded BSOD, or bugcheck, on a Windows machine. The procedures below guide you through the steps necessary to analyze and debug dump files.

For a downloadable copy of these procedures, click here: How%20To%20Debug%20Memory%20Dumps.doc

  • Download and install the Microsoft Debugging Tools from

  • Go to Start All Programs Debugging Tools For Windows WinDbg

  • Click on File Symbol File Path, enter:
    and click OK.

  • Click File Save Workspace so that your symbols path is saved for future use.

  • Now locate your memory dumps. Small memory dumps are usually located in %systemroot%\minidump and Kernel memory dumps are located in %systemroot%\MEMORY.DMP.

  • Go to File Open Crash Dump and load the file. You may get a message to save base workspace information. If so, choose No. Now you will get a debugging screen. It may take a little bit to run, since the symbols are downloaded as they are needed. Then you will see information such as:

Microsoft (R) Windows Debugger Version 6.7.0005.0
Copyright (c) Microsoft Corporation. All rights reserved.

Loading Dump File [\\hoem02\c$\windows\MEMORY.DMP]
Kernel Summary Dump File: Only kernel address space is available

Symbol search path is: SRV*c:\symbols*
Executable search path is:
Windows Server 2003 Kernel Version 3790 MP (4 procs) Free x86 compatible
Product: Server, suite: TerminalServer SingleUserTS
Built by: 3790.srv03_gdr.050225-1827
Kernel base = 0xe0b49000 PsLoadedModuleList = 0xe0be66a8
Debug session time: Wed May 9 02:01:49.965 2007 (GMT-7)
System Uptime: 6 days 22:51:23.840
Loading Kernel Symbols
Loading User Symbols
PEB is paged out (Peb.Ldr = 7ffff00c). Type ".hh dbgerr001" for details
Loading unloaded module list
* *
* Bugcheck Analysis *
* *

Use !analyze -v to get detailed debugging information.

BugCheck A, {4, 2, 0, e0b6136d}

Probably caused by : volsnap.sys ( volsnap!VspWriteVolumePhase35+3a )

Followup: MachineOwner

  • So far, we can tell that the bugcheck was caused by volsnap.sys, which is the Microsoft volume shadow copy driver. Use !analyze -v to get detailed debugging information. The most useful information is at the top of the analysis:

* *
* Bugcheck Analysis *
* *


An attempt was made to access a pageable (or completely invalid) address at an interrupt request level (IRQL) that is too high. This is usually caused by drivers using improper addresses.

If a kernel debugger is available get the stack backtrace.
Arg1: 00000004, memory referenced
Arg2: 00000002, IRQL
Arg3: 00000000, value 0 = read operation, 1 = write operation
Arg4: e0b6136d, address which referenced memory

  • From here, we can tell that volsnap.sys tried to read memory from an IRQL that was too high. This is usually caused by a bad driver, in this case, volsnap.sys.

  • Next, let's find out what process was calling volsnap.sys. Enter !thread in the kd> command line input box and look for the line that begins with Owning Process:

2: kd> !thread
THREAD faa03658 Cid 0568.1954 Teb: 7ffac000 Win32Thread: 00000000 RUNNING on processor 2
Not impersonating
DeviceMap e1003978
Owning Process fc1913b0 Image: cvd.exe
Wait Start TickCount 38443765 Ticks: 0

  • Now enter !process fc1913b0 0 (the hex number of the Owning Process), a space and the number 0.

2: d> !process fc1913b0 0
PROCESS fc1913b0 SessionId: 0 Cid: 0568 Peb: 7ffff000 ParentCid: 0218
DirBase: dd4a3000 ObjectTable: e141a910 HandleCount: 475.
Image: cvd.exe

  • We can now tell that the cvd.exe process (used by Commvault) called the volsnap.sys driver. Since volsnap.sys is a Microsoft driver, a quick check on TechNet reveals that there is an updated VSS package available for our server ( which addresses the problem.

Note: Writing debugging information must be configured on the machine prior to the BSOD in order to get a memory dump. This is done in the Advanced tab of system properties. Set it to "Kernel memory dump" in order to get the process information.


  1. This link is very helpful. Thank you so much.

  2. A very helpful article which I've just used to successfully find out why my server was BSOD'ing. Many thanks.


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