This article provides steps to add a VMKcore diagnostic partition on a local or shared disk post-installation using the esxcli
command line utility. A diagnostic partition can also be created using the vSphere Client. For more information, see:
VMware vSphere ESXi 5.5
VMware vSphere ESXi 5.1
VMware vSphere ESXi 7.0.0
VMware vSphere ESXi 8.0.0
VMware vSphere ESXi 6.5
VMware vSphere ESXi 6.7
VMware vSphere ESXi 5.0
VMware vSphere ESXi 6.0
To display the currently configured diagnostic coredump partition:
esxcli
command line utility:esxcli system coredump partition get
Active: mpx.vmhba2:C0:T0:L0:7
Configured: mpx.vmhba2:C0:T0:L0:7
To create a new diagnostic coredump partition on disk:
partedUtil
command line utility to create a new partition, 100 MB in size, with type 0xFC
= 252
. Ensure that other existing partitions on the same disk are not affected. For more information, see Using the partedUtil command line utility on ESXi and ESX (323144).esxcli
command line utility to list all accessible diagnostic partitions. Validate that the list of partitions includes the one created in step 3.esxcli system coredump partition list
Name Path Active Configured
--------------------- ------------------ ------ ----------
mpx.vmhba2:C0:T0:L0:7 /vmfs/devices/.... false false
esxcli
command line utility. Either specify a device explicitly, or use the Smart Activate feature to automatically select one of the accessible diagnostic partitions:esxcli system coredump partition set --partition="Partition_Name"
esxcli system coredump partition set --enable true
esxcli system coredump partition set --partition="mpx.vmhba2:C0:T0:L0:7"
esxcli system coredump partition set --enable true
esxcli system coredump partition set --enable true --smart
esxcli system coredump partition list
Name Path Active Configured
--------------------- ------------------ ------ ----------
mpx.vmhba2:C0:T0:L0:7 /vmfs/devices/.... true true
If a diagnostic partition is available on shared or local disks, it can be activated or deactivated across a group of ESXi 5.x/6.x hosts using Host Profiles.
To configure use of diagnostic coredump partitions using Host Profiles:
The environment that does not have Core Dump Configured will receive an Alarm as "Configuration Issues :- No Coredump Target has been Configured Host Core Dumps Cannot be Saved Error".
In the scenarios where the Core Dump partition is not configured and is not needed in the specific environment, you can suppress the Informational Alarm message, following the below steps,
The changes takes effect immediately and will suppress the alarm message.
To extract contents from the VMKcore diagnostic partition after a purple screen error, see Collecting diagnostic information from an ESX or ESXi host that experiences a purple diagnostic screen (308910).
To identify disks that can be used, see Identifying disks when working with VMware ESXi/ESX