Managing Diagnostic Partitions
Your host must have a diagnostic partition (dump partition) to store core dumps for debugging and for use by VMware technical support.
A diagnostic partition can be on the local disk where the ESXi software is installed. This is the default configuration for ESXi Installable. You can also use a diagnostic partition on a remote disk shared between multiple hosts. If you want to use a network diagnostic partition, you can install ESXi Dump Collector and configure the networked partition. See Managing Core Dumps with ESXi Dump Collector.
The following considerations apply:
Diagnostic Partition Creation
You can use the vSphere Client to create the diagnostic partition on a local disk or on a private or shared SAN LUN. You cannot use vicfg-dumppart to create the diagnostic partition. The SAN LUN can be set up with FibreChannel or hardware iSCSI. SAN LUNs accessed through a software iSCSI initiator are not supported.
Diagnostic Partition Management
You can use the vicfg-dumppart or the esxcli system coredump command to query, set, and scan an ESXi system’s diagnostic partitions. The vSphere Storage documentation explains how to set up diagnostic partitions with the vSphere Client and how to manage diagnostic partitions on a Fibre Channel or hardware iSCSI SAN.
Diagnostic partitions can include, in order of suitability, parallel adapter, block adapter, FC, or hardware iSCSI partitions. Parallel adapter partitions are most suitable and hardware iSCSI partitions the least suitable.