Support > Knowledge Base

Knowledge Base

Search the Knowledge Base:

Guided Search

Products:

Search In:

Setting up a VMKcore partition to capture purple screen output

Solution

Note: To support certain internal operations, ESX installations include a subset of standard Linux configuration commands (for example, network and storage configuration commands). Using these commands to perform configuration tasks can result in serious configuration conflicts and render some ESX functions unusable. Always work through the vSphere Client when configuring ESX, unless otherwise instructed in vSphere documentation or by VMware Technical Support.

ESX 3.X

Note: For Dell / IBM / FSJ local disk is generally /dev/sda. For HP the local disk is generally /dev/cciss/c0d0.

To set up the VMKcore partition on local or shared storage using fdisk :

Log into the ESX host using the root user via the console or SSH.
Run the command:

fdisk -l

The output appears similar to:

Disk /dev/sda: 73.2 GB, 73284976640 bytes
255 heads, 63 sectors/track, 8909 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Make note of the device node (highlighted in red).
Run the command:

fdisk -u /dev/sdX

where /dev/sdX represents the device node identified in step 3
Type n to make a new partition.
Type Enter when prompted for first cylinder (take default).
Type +100M for last cylinder/size.
Type t to change partition type.
Choose the highest numbered partition as this corresponds to the new partition that was just created.
Type fc to set the partition to vmkcore type.
Type w to write changes and exit.
Run the following command to activate the fc partition:

esxcfg-dumppart -a
Repeat step 2 to verify whether there is a partition with a type of fc on the disk.

To dump the information from the dump partition to a file, use the command:

vmkdump -d /dev/sdX

where /dev/sdXN is the device node of the fc partition

ESX 4.X

To set up the VMKcore partition on local or shared storage using fdisk:

Log into the ESX host using the root user via the console or SSH.
Run the command:

esxcfg-scsidevs -l

The output appears similar to:

mpx.vmhba0:C0:T0:L0
   Device Type: Direct-Access
   Size: 139890 MB
   Display Name: Local ServeRA Disk (mpx.vmhba0:C0:T0:L0)
   Plugin: NMP
   Console Device: /dev/sdb
   Devfs Path: /vmfs/devices/disks/mpx.vmhba0:C0:T0:L0
   Vendor: ServeRA   Model: 8k-l Mirror       Revis: V1.0
   SCSI Level: 2 Is Pseudo: false Status: on
   Is RDM Capable: false Is Removable: false
   Is Local: true
   Other Names:
      vml.0000000000766d686261303a303a30
Make note of the device node identified (highlighted in red), and make note of the identifier (highlighted in blue).
Run the command:

fdisk -u /dev/sdX

where /dev/sdX represents the device node identified in step 3
Type n to make a new partition.
Type Enter when prompted for first cylinder (take default).
Type +100M for last cylinder/size.
Type t to change partition type.
Choose the highest numbered partition as this corresponds to the new partition that was just created.
Typefc to set the partition to vmkcore type.
Typew to write changes and exit.
Run the command to activate the fc partition:

esxcfg-dumppart -a
Repeat step 2 to verify whether there is a partition with a type of fc on the disk.

To dump the information from the dump partition to a file, use the command:

esxcfg-dumpart --copy --devname /vmfs/devices/disks/<identifier>

where <identifier> is the identifier noted in step 3

Feedback

Actions

KB Article: 1000328
Updated: Oct 13, 2009

Products:
VMware ESX
Product Versions:
VMware ESX 2.5.x
VMware ESX 3.0.x
VMware ESX 3.5.x
VMware ESX 4.0.x
VMware ESXi 4.0.x Embedded
VMware ESXi 4.0.x Installable

Did this article help you?
This article resolved my issue. This article did not resolve my issue. This article helped but additional information was required to resolve my issue.
What can we do to improve this information? (2000 or fewer characters)