Novell might request a core dump when a server experiences a lockup or abend and other troubleshooting has failed to resolve the problem. A core dump is a copy of a NetWare server's memory at the time the server abended. Core dumps can be analyzed by Novell engineers and are often the key to finding software bugs. However, now that servers typically use large amounts of RAM, creating a core dump is less likely to be a routine troubleshooting procedure. Your ABEND.LOG file could be equally valuable for diagnosis.
IMPORTANT: You will be expected to install all necessary patches before Novell requests a core dump. To send a core dump file to Novell, you must first open a support incident, which will be billable. You will not be charged until the incident is resolved or closed. If the problem is a Novell bug and no patches were previously available, then there will be no charge.
The procedure for creating a core dump file follows, but your support representative can explain it when you call.
You can perform the following types of core dumps:
Full core dump copies all server memory to a local drive or device.
Full core dump minus cache copies all server memory except file cache (disk cache) to a local drive or device. The cacheless core dump is smaller, but it provides as much useful information as a full core dump.
A core dump can be started two ways:
The Type? prompt allows you to specify a full core dump or a cacheless core dump, as explained above.
The Device? prompt allows you to specify a local drive or a DOS-writeable device.
NOTE: Other types of core dumps might become possible in the future. Your Novell Technical Support representative will inform you if that is the case.
If the server is not completely frozen, you can enter the debugger by pressing: Shift+Shift+Alt+Esc. HINT: Press the left Shift key with the left hand, and press both the right Shift key and Alt with the right hand. Then press Esc with the most convenient finger of the left hand. Then enter .C and the server then displays core dump choices. When the core dump is finished, enter G to exit the debugger and to redisplay the System Console prompt. Or enter Q to exit to DOS.
If the server is not completely frozen, you can enter the debugger by pressing: Shift+Shift+Alt+Esc.
HINT: Press the left Shift key with the left hand, and press both the right Shift key and Alt with the right hand. Then press Esc with the most convenient finger of the left hand.
Then enter .C and the server then displays core dump choices.
When the core dump is finished, enter G to exit the debugger and to redisplay the System Console prompt. Or enter Q to exit to DOS.
After you start the core dump, you are asked to specify the DOS drive letter and file path that the memory image file will be written to. The size of the full image file will be approximately equal to the total RAM installed in the server. For a cacheless core dump, the size of the image file will be approximately equal to total RAM minus the amount of file cache (disk cache memory).
The drive can be any writable DOS device that contains enough storage space. But remember that it must be set up not only before the server abends, but before the server is booted.
When the image is written to a local hard disk on the server, the default name of the image file is C:COREDUMP.IMG. After the file is on the hard disk, it can be compressed, copied to diskettes, backed up to tape, or sent by FTP to ftp.novell.com (if you have opened a support incident).
The image file can also be written to a network drive later, after the server is up and running. This can be done using IMGCOPY.NLM or any other third-party NLM that provides this functionality. To locate IMGCOPY.NLM, use the search on the Patches and Files page on the Novell Web site.
Before sending the memory image to Novell, contact a support representative to open a support incident. You will be assigned to a Technical Support Engineer who will help you analyze the memory image file. The Technical Support Engineer will make arrangements to receive the image either in the regular mail or through the Internet and will advise you on the best media format to use.