by default the ASA creates the coredump files as snapshots and unless you enables the feature, it would not do anything. The Coredump is a system-wide snapshot of the ASA code at the time when a crash occurs. Coredumps are saved to disk allowing the user to export it later for off-site analysis by Cisco TAC . The Coredump was created since the current traceback information saved on the ASA after a crash, doesn't always provide enough information to determine the root cause of the problem. For ASA systems running Linux, the goal here is to take advantage of the built in LINUX OS functionality which, when configured, dumps core when unrecoverable problems are encountered.

In other words, a Coredump is the recorded state of the working memory of a computer program at a specific time, generally when the program has terminated abnormally (i.e. crashed). In practice, other key pieces of program state are usually dumped at the same time, including the processor registers, which may include the program counter and stack pointer, memory management information, and other processor and operating system flags and information. Coredumps can then be analyzed to diagnose or debug errors incomputer programs.

In order to disable this feature, you can issue the following command:

ciscoasa(config)# no coredump enable