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Roger’s VMware KB Articles worth reading

by Roger Lund

I thought this were worth reading, as it is better to read and experience, than the later.

Creating a second root user account


To create a second root user:
  1. Run the adduser -u 0 -o -g 0 -G 0,1,2,3,4,6,10 -M root2 command from the ESX server console.

    Omit the -M if you want a home directory created.

  2. Run the passwd root2 command to create a password.

Guidelines for Extending a VMFS Volume


An extended VMFS volume may contain from two to 32 physical extents. Each extent is either a primary partition, or a logical partition within an extended partition. These extents can be on one LUN or on multiple LUNs. In the latter case, some of these LUNs can have multiple extents on the volume.

To safely extend a VMFS volume:

  1. Perform a backup of the VMFS volume.
  2. Shut down all except one of your ESX Server machines.
  3. On this active ESX Server system, shut down all virtual machines that access the VMFS volume.
  4. Extend this volume. Keep in mind that this procedure reformats the volume you choose as the extent candidate, which overwrites any existing data on that volume.
  5. After the volume extension has successfully completed:
    • Restart the virtual machines that you shut down in step 3.
    • Restart your other ESX Server machines.
  6. Schedule regular backups for the extended VMFS volume.

    Warning: If one extent is corrupted or damaged, the entire volume becomes unusable.

Hardware and Firmware Requirements for 64-Bit Guest Operating Systems


VMware’s virtual machine monitor has traditionally used segmentation to provide isolation between the guest operating system and the virtual machine monitor. This is necessary because the guest operating system and virtual machine monitor share the linear address space.

Segmentation support is missing from the initial AMD64 processors (that is, revision C and earlier) while running in long mode. As a result, AMD64 processors prior to revision D do not have an efficient mechanism for isolating the virtual machine monitor from 64-bit guest operating systems.

A limited form of segmentation was reintroduced in long mode, in revision D AMD64 processors. As a result, AMD64 processors must be revision D or later to run 64-bit guest operating systems.

Note: Because AMD Opteron and Turion processors do not ship in revision D, AMD Opteron and Turion 64 processors must be revision E or later to run 64-bit guest operating systems.
Note: 64 bit guests are not supported for ESX versions 2.5.x and earlier.
For AMD Opteron‐based systems, the processors must be Opteron Rev E and later.
To ensure your processors support AMD64, please reference the following link – http://en.wikipedia.org/wiki/List_of_AMD_Opteron_microprocessors
Intel CPUs require EM64T and VT support in the chip and in the BIOS.
Intel EM64T CPUs do not have segmentation support in long mode. If the Intel EM64T CPU is VT-capable, it comes with hardware virtualization support (Intel’s Virtualization Technology). This hardware virtualization support allows Workstation and VMware Server to work around the lack of segmentation, making it possible to run 64-bit guest operating systems on Intel EM64T VT-capable CPUs.
(1) Firmware/BIOS support is required to enable Intel Virtualization Technology. Some systems (particularly laptops) do not have the necessary firmware/BIOS support to enable Intel Virtualization Technology, and cannot run 64-bit guest operating systems.
(2) In multi-processor systems, all processors must support compatible VT implementations. At a minimum, all processors must implement the same VMCS revision ID. In multi-processor systems with mixed processor steppings, 64-bit guest operating systems may not be supported.
Note: 64 bit guests are not supported for ESX versions 2.5.x and earlier.
Many servers that include CPUs with VT support might ship with VT disabled by default, and VT must be enabled manually. If your CPUs support VT but
you do not see this option in the BIOS, contact your vendor to request a BIOS version that lets you enable VT support.
To ensure your processors support VT, please reference the following link – http://compare.intel.com/pcc/default.aspx?familyid=5&culture=en-US
VT should be listed under ‘Other Intel Technologies’ if it is a feature of the CPU.
32-Bit CPUs
Please note that Workstation and VMware Server require a 64-bit CPU to run a 64-bit guest operating system. While it is theoretically possible to emulate a 64-bit instruction set on 32-bit hardware, doing so most likely results in unacceptable performance degradation.

VMware distributes a free utility that can be used to determine whether or not your CPU is suitable for running 64-bit guest operating systems. You can download this utility from the VMware Web site at http://www.vmware.com/download/ws/drivers_tools.html (scroll down to Processor Check for 64-Bit Compatibility). VMware Server includes this utility in its product distribution, so you don’t need to download an additional tool.

Workstation 5.5 and higher and VMware Server (all versions) support virtual machines with 64-bit guest operating systems only on host machines that have one of the supported 64-bit processors:

  • AMD Athlon 64, revision D or later
  • AMD Opteron, revision E or later
  • AMD Turion 64, revision E or later
  • AMD Sempron, 64-bit-capable revision D or later (experimental support)
  • Intel EM64T VT-enabled processors (experimental support)

Is Running Older VMware Tools in ESX Server Guests Supported?


“When you install a patched version of ESX Server, VMware expects you to upgrade VMware Tools to the latest version, included with that release. If you report a problem with a virtual machine that has an older version of the VMware Tools installed in the guest operating system, VMware Technical Support may ask you to upgrade the VMware tools to the version included with the ESX Server Patch in the process of troubleshooting that problem.

Unable to boot after ESX upgrade


To troubleshoot the inability to boot your ESX host after an upgrade:
  1. Determine if you can boot into Linux/Troubleshooting mode.
  2. If you can boot in to Linux/Troubleshooting, run the following commands:
    • esxcfg-boot -p
    • esxcfg-boot -b
    • esxcfg-boot -r

  3. If booting into Linux/Troubleshooting mode fails, ensure that the storage is disconnected and do a fresh installation. Ensure to select Keep Virtual Machines and VMFS Volumes intact.
  4. Reboot the ESX host.

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