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.

The following considerations apply:

>> A diagnostic partition cannot be located on an iSCSI LUN accessed through the software iSCSI or dependent hardware iSCSI adapter. For more information about diagnostic partitions with iSCSI, see General Boot from iSCSI SAN Recommendations in the vSphere Storage documentation.

>> Each host must have a diagnostic partition of 110MB. If multiple hosts share a diagnostic partition on a SAN LUN, the partition should be large enough to accommodate core dumps of all hosts.

>>If a host that uses a shared diagnostic partition fails, reboot the host and extract log files immediately after the failure. Otherwise, the second host that fails before you collect the diagnostic data of the first host might not be able to save the core dump.

Diagnostic Partition Creation:

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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.

Managing Core Dumps:

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With esxcli system coredump, you can manage local diagnostic partitions or set up core dump on a remote server in conjunction with ESXi Dump Collector. For information about ESXi Dump Collector, see the vSphere Networking documentation.

Managing Local Core Dumps with ESXCLI:

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The following example scenario changes the local diagnostic partition with ESXCLI. Specify one of the connection options listed in Connection Options in place of <conn_options>.

To manage a local diagnostic partition

1: Show the diagnostic partition the VMkernel uses and display information about all partitions that can be used as diagnostic partitions.

esxcli <conn_options> system coredump partition list

2: Deactivate the current diagnostic partition.

esxcli <conn_options> system coredump partition set –unconfigure

The ESXi system is now without a diagnostic partition, and you must immediately set a new one.

3: Set the active partition to naa.<naa_ID>.

esxcli <conn_options> system coredump partition set –partition=naa.<naa_ID>

4: List partitions again to verify that a diagnostic partition is set.

esxcli <conn_options> system coredump partition list

If a diagnostic partition is set, the command displays information about it. Otherwise, the command shows that no partition is activated and configured.

Managing Core Dumps with ESXi Dump Collector:

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By default, a core dump is saved to the local disk. You can use ESXi Dump Collector to keep core dumps on a network server for use during debugging. ESXi Dump Collector is especially useful for Auto Deploy, but supported for any ESXi 5.0 host. ESXi Dump Collector supports other customization, including sending core dumps to the local disk.

ESXi Dump Collector is included with the vCenter Server autorun.exe application. You can install ESXi Dump Collector on the same system as the vCenter Server service or on a different Windows or Linux machine.

You can configure ESXi Dump Collector by using the vSphere Client or ESXCLI. Specify one of the connection options listed in Connection Options in place of <conn_options>.

To manage core dumps with ESXi Dump Collector:

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1: Set up an ESXi system to use ESXi Dump Collector by running esxcli system coredump.

esxcli <conn_options> system coredump network set –interface-name vmk0 –server-ipv4=1-XX.XXX –port=6500

You must specify a VMkernel port with –interface-name, and the IP address and port of the server to send the core dumps to. If you configure an ESXi system that is running inside a virtual machine, you must choose a VMkernel port that is in promiscuous mode.

2: Enable ESXi Dump Collector.

esxcli <conn_options> system coredump network set –enable=true

3: (Optional) Check that ESXi Dump Collector is configured correctly.

esxcli <conn_options> system coredump network get

The host on which you have set up ESXi Dump Collector sends core dumps to the specified server by using the specified VMkernel NIC and optional port.

Managing Local Core Dumps with ESXCLI:

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The following example scenario changes the local diagnostic partition with ESXCLI. Specify one of the connection options listed in Connection Options in place of <conn_options>.

To manage a local diagnostic partition

1: Show the diagnostic partition the VMkernel uses and display information about all partitions that can be used as diagnostic partitions.

esxcli <conn_options> system coredump partition list

2: Deactivate the current diagnostic partition.

esxcli <conn_options> system coredump partition set –unconfigure

The ESXi system is now without a diagnostic partition, and you must immediately set a new one.

3: Set the active partition to naa.<naa_ID>.

esxcli <conn_options> system coredump partition set –partition=naa.<naa_ID>

4: List partitions again to verify that a diagnostic partition is set.

esxcli <conn_options> system coredump partition list

If a diagnostic partition is set, the command displays information about it. Otherwise, the command shows that no partition is activated and configured.

Additional Information : ESXi Network Dump Collector in VMware vSphere 5.x/6.0