Language :

Extracting a core dump file from the diagnostic partition following a purple diagnostic screen error (1002769)

 Click here to view full document

This article provides information on extracting a core dump file from the diagnostic partition following a purple diagnostic screen error.

During a purple diagnostic screen, ESXi/ESX attempts to write a VMkernel core dump to a previously-configured VMKCore (type 0xFC) partition. This file is normally created during start up or while collecting vm-support logs.

In ESXi 5.5 and higher, a VMkernel core dump may be written to a dump file, either in addition or instead of a partition. For such cases, see Generating a VMkernel zdump manually from a dump file in ESXi (2081902).

For more information on related topics, see:
The command line utility for extracting a VMkernel core dump differs between versions of ESXi/ESX.

vSphere 4.0 and higher

Use command-line tools on the ESXi host to identify the diagnostic partition and copy its contents to a file.

  1. Log in to the ESXi/ESX host:

  2. Determine the device identifiers for the diagnostic partition(s) by running one of these commands:

    • esxcli system coredump partition list
    • esxcfg-dumppart -t

    You see output mentioning a device name and full path to the partition (

    mpx.vmhba1:C0:T0:L0:7 /vmfs/devices/disks/mpx.vmhba1:C0:L0:7

  3. A core dump file is between 100 and 300 MB in size. Change to a directory with sufficient space to store the core dump file, such as on a Datastore.

    For example:

    cd /vmfs/volumes/DatastoreName/

  4. Copy the partition contents to a file by running the esxcfg-dumppart command, specifying the full path from step 2:

    esxcfg-dumppart --copy --devname "/vmfs/devices/disks/identifier" --zdumpname /vmfs/volumes/datastore1/filename.1

    For example:

    esxcfg-dumppart --copy --devname "/vmfs/devices/disks/mpx.vmhba2:C0:T0:L0:2" --zdumpname /vmfs/volumes/datastore1/hostname-date-zdump

  5. Use the Datastore Browser or scp to retrieve the produced zdump file, and share it with VMware Support.

ESXi/ESX 3.x

To generate a core dump file on ESXi/ESX 3.x:

  1. Log into the ESXi/ESX host:

  2. Determine the device identifiers for the core partition(s) by running the command:

    esxcfg-dumppart -t

    You see one of these outputs:

    • vmhba1:0:0:7 /vmfs/devices/disks/vmhba1:0:0:7
    • naa.600508b1001030374543433532300700:7 /vmfs/devices/disks/naa.600508b1001030374543433532300700:7
    • naa.6d4ae520a23d1500178db21c1837fead:7 /vmfs/devices/disks/naa.6d4ae520a23d1500178db21c1837fead:7
      naa.600508b1001030374543433532300700:7 /vmfs/devices/disks/naa.600508b1001030374543433532300700:7


  3. If there is no output in step 2, set one of the volumes as the dump partition using the command:

    esxcfg-dumppart -s naa.ID

  4. Activate the partition using the command:

    # esxcfg-dumppart -a
    Dump Partition activated.


  5. Change to a directory with sufficient space to store the core dump file.

    For example:

    cd /vmfs/volumes/DatastoreName/

  6. Dump the partition contents to a file by running the command:

    vmkdump --devname "identifier"

    Where identifier is the value recorded in step 2.

    For example:

    vmkdump --devname "/vmfs/devices/disks/vmhba1:0:0:0:7"

Additional Information

For translated versions of this article, see:

10/18/2016 - Added ESXi 6.0 to Products
11/29/2011 - Added ESXi 5.0 to Products
07/24/2012 - Added note that in vMA 5.0 the
vifpinit command is replaced with vifptarget
11/20/2012 - Added ESXi 5.1 to Products
3/10/2017 8:00 AM
Data Conversion
Tashi Namgyal