Wednesday, March 25, 2009

SAP system crashes

Core dump – when SAP’s system work process crashes with error SYSTEM_CORE_DUMPED a text (core) file is always written to the subdirectory /usr/sap/SID//work. Such a file is used to facilitate troubleshooting afterwards. Content of file is a “snapshot” of program status, memory dump, C Stack, etc. in time when error occurred. Name of file is simply “core” if it wasn’t customized in different way. Usually only one or more work processes die and kernel restarts them automatically. System is able to recover from this faulty situation by it self. Core dump is sometimes called by term “mode termination”.

Signal and core dump – this SAP’s system work process crashes after signal (e.g. $$$) received from operating system. Entry is created in SysLog (TA SM21). It is same as core dump just invoked by operation system.

System (kernel) panic w/o data page fault – this is unrecoverable error causing operating system to crash. This situation is caused by operational system issue in most cases, like memory protection, addressing, etc. System is then trap and panic with a data page fault.
Here’s an example of system panic message which user gets while working in system going to crash. It was taken from SAP system based on Basis 4.6D.

1 comment:

Anonymous said...

"is always written to the subdirectory /usr/sap/SID//work" <-- It's not true. It's written to the working directory of the process which caused the fault.