This is something very interesting which gained support with the release of vSAN 6.5. It will be of interest to those customers who boot their ESXi hosts from USB/SD devices, and also have vSAN configured. One long-standing restriction with this configuration was the inability to boot from USB/SD when the amount of memory in the host is over 512GB. This is because we could not guarantee that the memory dump would fit in the pre-sized core dump partition. Well, now we have the ability to resize the core dump partition, even when it resides on a USB/SD device. The guidance for sizing the core dump partition size relates to the number of disk groups, cache size and amount of memory on the host. The details on how to do it can be found in KB article 2147881. A script to resize the core dump partition, along with the instructions and some worked examples are included in the KB. Note that the script will only run if (1) ESXi version 6.5 is detected and (2) vSAN is enabled.

It is important to follow these guidelines if you boot your ESXi hosts from USB/SD devices, plan to enable vSAN and have more than 512GB of memory on the ESXi hosts.