The savecore command runs automatically after a system crash to retrieve the crash dump information from the dump device and writes the information into a set of files. Afterwards, the savecore command can be invoked on the same system or another system to expand the compressed crash dump files.
Crash dump files are saved in a predetermined directory, which by default is /var/crash/. In previous releases, crash dump files were overwritten when a system rebooted unless you manually enabled the system to save the images of physical memory in a crash dump file. Now, the saving of crash dump files is enabled by default.