If the size of your available core dump partition size is insufficient, you can configure ESXi to generate core dump as a file.

Typically, the core dump partition for new installations of ESXi 5.5 and later is 2.5GB. For upgrades from previous releases to ESXi 5.5, the core dump partition is limited to 100MB for ESXi crashes. For many large systems, this limit is not enough space and the core dump log files are truncated. For upgrades with limits on 100MB partitions, during the boot process the system might create a core dump file on a VMFS datastore. If it does not create a core dump file, you can manually create the file.

Note: Software iSCSI and software FCoE are not supported for core dump file locations.


Install vCLI or deploy the vSphere Management Assistant (vMA) virtual machine. See Getting Started with vSphere Command-Line Interfaces. For troubleshooting, run esxcli commands in the ESXi Shell.


  1. Create a VMFS datastore core dump file by running the following command:
    esxcli system coredump file add -d DATASTORE_UUID -f FILENAME
  2. Verify that the file has been created:
    esxcli system coredump file list
    You can see the output similar to the following:
    Path                                             Active Configured Size
    ------------------------------------------------ ------ ---------- ---------
    /vmfs/volumes/52b021c3-.../vmkdump/test.dumpfile false  false      104857600
  3. Set the core dump file for the host:
    esxcli system coredump file set -p /vmfs/volumes/DATASTORE_UUID/vmkdump/FILENAME

    For example:

    esxcli system coredump file set -p /vmfs/volumes/52b021c3-f6b3da50-4c76-001d0904c5a5/vmkdump/test.dumpfile

  4. Verify that the core dump file is active and configured:
    esxcli system coredump file list
    The output similar to the following indicates that the core dump file is active and configured:
    Path                                             Active Configured Size
    ------------------------------------------------ ------ ---------- ---------
    /vmfs/volumes/52b021c3-.../vmkdump/test.dumpfile True   True       104857600

What to do next

For information about other commands you can use to manage the core dump files, see the vSphere Command-Line Interface Reference documentation.