memory dump

The debugging information can be written to different file formats (also known as memory dump files) when your computer stops unexpectedly because of a Stop error (also known as a "blue screen," system crash, or bug check). You can also configure Windows not to write debugging information to a memory dump file.

Windows can generate any one of the following memory dump file types:

• Complete memory dump
• Kernel memory dump
• Small memory dump (64 KB)

Complete memory dump

A complete memory dump records all the contents of system memory when your computer stops unexpectedly. A complete memory dump may contain data from processes that were running when the memory dump was collected.

If you select the Complete memory dump option, you must have a paging file on the boot volume that is sufficient to hold all the physical RAM plus 1 megabyte (MB).

If a second problem occurs and another complete memory dump (or kernel memory dump) file is created, the previous file is overwritten.

Notes

• In Windows Vista, Windows 7, Windows Server 2008 and in Windows Server 2008 R2, the paging file can be on a partition that differs from the partition on which the operating system is installed. 
• In Windows Vista and Windows Server 2008, to put a paging file on another partition, you must create a new registry entry that is named DedicatedDumpFile. You can define the size of the paging file by using a new registry entry that is named DumpFileSize.
• For more information about how to do this, visit the following Microsoft Web site:
  969028 How to generate a kernel or a complete memory dump file in Windows Server 2008


• In Windows 7 and Windows Server 2008 R2, to put a paging file on another partition, it is not mandatory to use DedicatedDumpFile registry entry.
• The Complete memory dump option is not available on computers that are running a 32-bit operating system and that have 2 gigabytes (GB) or more of RAM. For more information, see the Specify what

 

Kernel memory dump

A kernel memory dump records only the kernel memory. This speeds up the process of recording information in a log when your computer stops unexpectedly. You must have a pagefile large enough to accommodate your kernel memory. For 32-bit systems, kernel memory is usually between150MB and 2GB. Additionally, on Windows 2003 and Windows XP, the page file must be on the boot volume. Otherwise, a memory dump cannot be created.

This dump file does not include unallocated memory or any memory that is allocated to User-mode programs. It includes only memory that is allocated to the kernel and hardware abstraction layer (HAL) in Windows 2000 and later, and memory allocated to Kernel-mode drivers and other Kernel-mode programs. For most purposes, this dump file is the most useful. It is significantly smaller than the complete memory dump file, but it omits only those parts of memory that are unlikely to have been involved in the problem.

If a second problem occurs and another kernel memory dump file (or a complete memory dump file) is created, the previous file is overwritten when the 'Overwrite any existing file' setting is checked.

Small memory dump

A small memory dump records the smallest set of useful information that may help identify why your computer stopped unexpectedly. This option requires a paging file of at least 2 MB on the boot volume and specifies that Windows 2000 and later create a new file every time your computer stops unexpectedly. A history of these files is stored in a folder.

This dump file type includes the following information:

• The Stop message and its parameters and other data
• A list of loaded drivers
• The processor context (PRCB) for the processor that stopped
• The process information and kernel context (EPROCESS) for the process that stopped
• The process information and kernel context (ETHREAD) for the thread that stopped
• The Kernel-mode call stack for the thread that stopped

This kind of dump file can be useful when space is limited. However, because of the limited information included, errors that were not directly caused by the thread that was running at the time of the problem may not be discovered by an analysis of this file.

If a second problem occurs and a second small memory dump file is created, the previous file is preserved. Each additional file is given a distinct name. The date is encoded in the file name. For example, Mini022900-01.dmp is the first memory dump generated on February 29, 2000. A list of all small memory dump files is kept in the %SystemRoot%\Minidump folder.

Configure the dump type

To configure startup and recovery options (including the dump type), follow these steps.

Note Because there are several versions of Microsoft Windows, the following steps may be different on your computer. If they are, see your product documentation to complete these steps.

1. Click Start, and then click Control Panel.
2. Click Performance and Maintenance, and then click System.
3. On the Advanced tab, click Settings under Startup and Recovery.

NOTE: You must restart Windows in order for your changes to take affect.

Tools for the various dump types

You can load complete memory dumps and kernel memory dumps with standard symbolic debuggers, such as I386kd.exe. I386kd.exe is included with the Windows 2000 Support CD-ROM.

Load small memory dumps by using Dumpchk.exe. Dumpchk.exe is included with the Support Tools for Windows 2000 and Windows XP. You can also use Dumpchk.exe to verify that a memory dump file has been created correctly.

For more information about how to use Dumpchk.exe in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:

315271  How to use Dumpchk.exe to check a memory dump file

For more information about how to use Dumpchk.exe in Windows 2000, click the following article number to view the article in the Microsoft Knowledge Base:

156280  How to use Dumpchk.exe to check a memory dump file

For more information about Windows debugging tools, visit the following Microsoft Web site: