Spare array LUN requirement for core dumps
For both stand-alone ONTAP systems and nodes in HA pairs, you must create a spare array LUN of adequate size to hold core dumps if no spare disk is available.
On a system that uses both disks and array LUNs, a spare array LUN is not required for a core dump if a spare disk is available. If neither a spare array LUN nor a spare disk is available, there is no place for the core to be dumped.
A core dump contains the contents of memory and NVRAM. During a system panic, ONTAP dumps core to a spare array LUN or spare disk, if a spare exists. Upon reboot, the core is read from the spare and saved to a core dump on the root filesystem. Technical support can then use the core dump to help troubleshoot the problem.
The Hardware Universe contains the minimum spare core array LUN size for each platform.