A core dump is the state of working memory in the event of host failure. By default, a core dump is saved to the local disk. In the case of Auto Deploy where there may not be a local disk the core dump will be saved to a ramdisk in memory, which is a problem because the core dumps will be lost when the host reboots.
To solve this dilemma vSphere 5.0 includes a new feature called the ESXi Dump Collector. The Dump Collector enables you redirect ESXi host core dumps onto a network server. It’s very easy to install and configure. The dump collector is included as part of the vCenter Server Appliance (VCSA) and requires no extra setup. To install the dump collector on Windows simply load the vCenter installation media, launch autorun and from the main install menu choose “ESXi Dump Collector”.
During the install you will be asked where on the host you want to store the core dumps, by default the dump repository is 2GB, which should be sufficient for most environments.
You will also be asked if you want to do a Standalone installation or integrate the dump collector with vCenter. If you choose the VMware vCenter Server Installation it will register the Dump Collector plug-in with the vCenter server.
The final step is to use the ESXCLI to configure each host to use the Dump Collector. The screen shot below shows the commands to do this.
Now anytime your ESXi 5.0 host generates a core dump the file will be saved on the network server and available for analysis. The screen shots below show the file being copied to the network server when my ESXi host PSODs. I also provided a listing of the corefile for reference.