How to – display/activate a diagnostic coredump partition on your ESXi 5.x Host

If your ESXi Host 5.0/5.1/5.5 experiences a purple diagnostic screen of death (PSOD), it hopefully creates a diagnostic coredump. This dump contains useful information for a root cause analysis.

If there is no available disk partition for a coredump on your ESXi host, you will get the following configuration issue:

“No vmkcore disk partition is available and no network coredump server has been configured. Host core dumps cannot be saved.”

In this case the following steps will help you:

You can display the currently active diagnostic partition with the following command (via console session to your ESXi host):

esxcli system coredump partition get

You will see an output like:


If you want your ESXi host to select and activate an accessible partition automatically, use the following command (you need a partition with at least 100 MB of free space):

esxcli system coredump partition set –enable=true –smart

If you want to define a dedicated partition for the diagnostic coredump use these commands:

First list all accessible diagnostic partitions:

esxcli system coredump partition list

You will see an output like:


Now specify a partition you want:

esxcli system coredump partition set –partition=”device_path_name”

In this example we configure mpx.vmhba32:C0:T0:L0:7 as a coredump partition:

And now we activate the specified partition using:

esxcli system coredump partition set –enable true

To validate our configuration use:

esxcli system coredump partition list

We should get something like:



  1. Pavel

    Thanks much! You fixed my problem! There’s surprisingly little information about this. Even vmware’s kb was of little help.

  2. Gustavo

    Great article! Do you know if enabling network dump collector prevents the memory dumps to be saved on the ESXi disk?

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