In some failure situations, an Oracle engineer might need to analyze a system core dump file to determine the root cause of a system failure. Although the core dump process is enabled by default, configure your system so that the core dump file is saved in a location with adequate space. You also might want to change the default core dump directory to another locally mounted location so that you can better manage any system core dumps. In certain testing and pre-production environments, this is recommended because core dump files can take up a large amount of file system space.
During a system core dump, the system saves the content of kernel core memory to the dump device. The dump content is compressed during the dump process at a 3:1 ratio; that is, if the system were using 6 Gbytes of kernel memory, the dump file is about 2 Gbytes. For a typical system, the dump device must be at least one third the size of the total system memory.
Swap space is used to save the dump of system memory. By default, Oracle Solaris software uses the first swap device that is defined. This first swap device is known as the dump device.
For Oracle Solaris software, use dumpadm to enable the core dump process. For details, refer to Troubleshooting System Administration Issues in Oracle® Solaris 11.4 at https://docs.oracle.com/cd/E37838_01/.
For instructions on how to configure and initiate forced crash dumps (kernel core dumps) in x86 Oracle Solaris and collect information for troubleshooting system hangs, go to My Oracle Support at https://support.oracle.com, and refer to the Knowledge Article Doc ID 1003085.1.
For Oracle Linux software, use kdump to enable the core dump process. For details, refer to the Oracle Linux Administrator's Guide for Release 7 at https://docs.oracle.com/cd/E52668_01/.