How to use the Sqldumper.exe utility to generate a dump file in SQL Server 2005

The Sqldumper.exe utility is included with Microsoft SQL Server 2005. This article describes how to use the Sqldumper.exe utility to generate a dump file for Watson error reporting or for debugging tasks.

You can use the Sqldumper.exe utility to generate a dump file on demand for any Microsoft Windows application. For example, you can generate a dump file for debugging an application problem when a computer that is running SQL Server 2005 is not responding to user requests. A dump file can be a mini-dump file, a full dump file, or a filtered dump file.

However, you cannot use the Sqldumper.exe utility for general purpose debugging. For more information about general purpose debugging, visit the following Microsoft Web site: The SQL Server process calls the Sqldumper.exe utility internally to generate a dump file when the process experiences any exceptions. SQL Server passes flags to the Sqldumper.exe utility. You can use trace flags to change the flags that SQL Server passes to the utility in the context of an exception or in the context an assertion. These trace flags are in the range from 2540 to 2559. You can use these trace flags to generate certain types of dump files.

How to obtain a Microsoft Windows application process identifier

To generate a dump file by using the Sqldumper.exe utility, you must have the process identifier of the Windows application for which you want to generate a dump file. To obtain the process identifier, follow these steps:

1. Press CTRL+ALT+DELETE, and then click Task Manager.
2. In the Windows Task Manager dialog box, click the Processes tab.
3. On the View menu, click Select Columns.
4. In the Select Columns dialog box, click to select the PID (Process Identifier) check box, and then click OK.
5. Notice the process identifier of the Windows application for which you want to generate a dump file. For the SQL Server application, notice the process identifier of the Sqlservr.exe process.
6. Close Task Manager.

You can also obtain the process identifier of the SQL Server application that is running on your computer by using the SQL Server error log file. For example, part of the SQL Server error log file resembles the following:The number that appears after Server process ID is the process identifier for the Sqlservr.exe process.

How to run the Sqldumper.exe utility

Run the Sqldumper.exe utility under the context of the folder where SQL Server originally installed the utility. By default, the installation path of the Sqldumper.exe utility is as follows:Note SQLServerInstallDrive is a placeholder for the drive where you installed SQL Server 2005.

To generate a dump file by using the Sqldumper.exe utility, follow these steps:

1. Open the following folder:
   SQLServerInstallDrive:\Program Files\Microsoft SQL Server\90\Shared
2. Make sure that the Dbghelp.dll file is in this folder.
3. Click Start, click Run, type cmd, and then click OK.
4. At the command prompt, type the following command, and then press ENTER:
   cd SQLServerInstallDrive:\Program Files\Microsoft SQL Server\90\Shared
5. To generate a specific kind of dump file, type the corresponding command at the command prompt, and then press ENTER:
   • Full dump file
     Sqldumper.exe ProcessID 0 0x01100
   • Mini-dump file
     Sqldumper.exe ProcessID 0 0x0120
   • Mini-dump file that includes indirectly referenced memory
     Sqldumper.exe ProcessID 0 0x0120:40
   • Filtered dump file
     Sqldumper.exe ProcessID 0 0x8100
   Note ProcessID is a placeholder for the process identifier of the Windows application for which you want to generate a dump file.

If the Sqldumper.exe utility runs successfully, the utility generates a dump file in the folder where the utility is installed.

The dump file that the Sqldumper.exe utility generates has a file name pattern that resembles the following: In this pattern, xxxx is an increasing number that is determined based on other files that have a similar file name in the same folder. If you already have files in the folder that have file names in the specified pattern, you may have to compare the date and the time that the file was created to identify the file that you want.

Additional information and considerations

When the Sqldumper.exe utility generates a dump file for a Windows application, the dump file may be as large as the memory that the Windows application is currently using. Make sure that sufficient disk space is available on the drive to which the Sqldumper.exe utility is writing the dump file.

You can specify the directory where you want the Sqldumper.exe utility to write the dump file. The directory must already exist before you run the Sqldumper.exe utility. Otherwise, the Sqldumper.exe utility will fail. Do not use a UNC path as a location for the dump file. The following is an example of how to specify the dump file location of the mini-dump file:

1. Click Start, click Run, type cmd, and then click OK.
2. At the command prompt, type the following command, and then press ENTER:
   cd SQLServerInstallDrive:\Program Files\Microsoft SQL Server\90\Shared
3. Type the following command at the command prompt, and then press ENTER:
   Sqldumper.exe ProcessID 0 0x0120 0 MdumpPath
   Note MdumpPath is a placeholder for the directory where you want the Sqldumper.exe utility to write the dump file.

If you specify a full dump file or a filtered dump file to be generated, the Sqldumper.exe utility may take several minutes to generate the dump file. The time depends on the following variables:

• The amount of memory that the Sqldumper.exe utility is currently using
• The speed of the drive to which the utility is writing the dump file

During this time, the Sqldumper.exe utility will not process commands. You will notice that the server has stopped responding. Additionally, a cluster failover may occur.

To run the Sqldumper.exe utility, you must log on to Windows by using one of the following methods:

• Use an account that is a member of the administrators group on the computer.
• Use the same user account under which the SQL Server service is running.

For the Sqldumper.exe utility to work successfully through Remote Desktop or through Terminal Services, you must start Remote Desktop or Terminal Services in console mode. For example, to start Remote Desktop in console mode, click Start, click Run, type mstsc /console, and then click OK. Be aware that if the target server runs Windows 2000, the /console option is silently ignored. You can connect to the server through Remote Desktop. But you will not be using the console session.

If you notice that no dump file has been generated in the current folder after you run the Sqldumper.exe utility, review the information that the utility has generated at the command line to try to determine the possible cause of the failure. This information is also logged in the Sqldumper_errorlog.log file in current directory. The following are two possible error messages and their causes:An invalid Process ID was passed to the Sqldumper.exe utility.An invalid parameter was passed to the Sqldumper.exe utility.

If an error message that resembles the following is generated, you can safely ignore this message:

Cluster failovers and the Sqldumper.exe utility

In cluster failover scenarios, the SQL Server resource DLL now can obtain a dump file before the failover occurs. When the SQL Server resource DLL determines that a SQL Server resource has failed, the SQL Server resource DLL uses the Sqldumper.exe utility to obtain a dump file of the SQL Server process. To make sure that the Sqldumper.exe utility successfully generates the dump file, you must set the following three properties as prerequisites:

• SqlDumperDumpTimeOut
  A user-specified time-out. The resource DLL waits for the dump file to be completed before the resource DLL stops the SQL Server service.
• SqlDumperDumpPath
  The location where the Sqldumper.exe utility generates the dump file.
• SqlDumperDumpFlags
  Flags that the Sqldumper.exe utility uses.

If any one of the properties is not set, the Sqldumper.exe utility cannot generate the dump file. A warning message will be logged both in the event log and in the cluster log whenever the resource is brought online.

To set the Sqldumper.exe utility properties for cluster failover, follow these steps:

1. Click Start, click Run, type cmd, and then click OK.
2. For each property, type the corresponding command at the command prompt, and then press ENTER:
   • The SqlDumperDumpFlags property
     To set the SqlDumperDumpFlags property for a specific kind of dump file, type the corresponding command at the command prompt, and then press ENTER:
     • All thread full dump file
       cluster resource "SQL Server" /priv SqlDumperDumpFlags = 0x01100
     • All thread mini-dump file
       cluster resource "SQL Server" /priv SqlDumperDumpFlags = 0x0120
     • Filtered all thread dump file
       cluster resource "SQL Server" /priv SqlDumperDumpFlags = 0x8100
   • The SqlDumperDumpPath property
     cluster resource "SQL Server" /priv SqlDumperDumpPath= DirectoryPath
     Note DirectoryPath is a placeholder for the directory in which the dump file will be generated, and it should be specified in quotation marks (" ").
   • The SqlDumperDumpTimeOut property
     cluster resource "SQL Server" /priv SqlDumperDumpTimeOut= Timeout
     Note Timeout is a placeholder for the time-out in milliseconds (ms).
     
     The time that the utility takes to generate a dump file of a SQL Server process depends on the computer configuration. For a computer that has lots of memory, the time could be significant. To obtain an estimate of the time that the process takes, use the Sqldumper.exe utility to manually generate a dump file. The valid values for the SqlDumperDumpTimeOut property are from 10000 ms to MAXDWORD. MAXDWORD represents the highest value in the range of the DWORD data type (4294967295).

To verify that the settings have been enabled, you can run the following command:
To remove the Sqldumper.exe utility properties for cluster failover, follow these steps:

1. Click Start, click Run, type cmd, and then click OK.
2. For a specific property, type the corresponding command at the command prompt, and then press ENTER:
   • The SqlDumperDumpFlags property
     cluster resource "SQL Server" /priv:SqlDumperDumpFlags /usedefault
   • The SqlDumperDumpPath property
     cluster resource "SQL Server" /priv:SqlDumperDumpPath /usedefault
   • The SqlDumperDumpTimeOut property
     cluster resource "SQL Server" /priv:SqlDumperDumpTimeOut /usedefault