VMware

VCP 6 – DCV Study Guide: Section 10 – Objective 10.1

Section 10: Administer and Manage vSphere Virtual Machines

Objective 10.1: Configure Advanced vSphere Virtual Machine Settings
  • Identify available virtual machine configuration settings

Virtual Machine Option Overview

You can view or change virtual machine settings from the vSphere Web Client. Not all options are available to every virtual machine and some options rarely need to change from their defaults.

The host that the virtual machine runs on and the guest operating system must support any configurations that you make.

When you select Edit Settings from a virtual machine right-button menu and click VM Options, you can select one of the following options.

Virtual Machine Options

Options Description
General Options Virtual machine name and location of the virtual machine configuration file and virtual machine working location. View or change the type and version of the guest operating system.
VMware Remote Console Options Locking behavior and settings for simultaneous connections,
VMware Tools Power Controls behavior, VMware Tools scripts, automatic upgrades, and time synchronization between the guest and host.
Power Management Virtual machine Suspend behavior and wake on LAN.
Boot Options Virtual machine boot options. Add a delay before booting, force entry into the BIOS or EFI setup screen, or set reboot options.
Advanced Advanced virtual machine options. See the table below.
Fibre Channel NPIV Virtual node and port World Wide Names (WWNs).

When you select Edit Settings from a virtual machine right-button menu, click VM Options, and click Advanced, you can select one of the following options.

Advanced Virtual Machine Options

Advanced Options Description
Settings Specify acceleration and logging settings.
Debugging and statistic Specify the level of debugging information that is being collected.
Swap file location Specify the swap file location.
Configuration Parameters View, modify, or add configuration parameters.
Latency Sensitivity Set a value for latency sensitivity.
  • Interpret virtual machine configuration files (.vmx) settings

View the Virtual Machine Configuration and Working File Location

You can view the location of the virtual machine configuration and working files. You can use this information when you configure backup systems.

Prerequisites

Verify that the virtual machine is powered off.

Procedure

1. Right-click a virtual machine in the inventory and select Edit Settings.

2. Click VM Options tab and expand General Options.

The path to the location of the virtual machine configuration file appears in the VM Config File text box. The path to the virtual machine working location appears in the VM Working Location text box.

What Is a Virtual Machine?

A virtual machine is a software computer that, like a physical computer, runs an operating system and applications. The virtual machine consists of a set of specification and configuration files and is backed by the physical resources of a host. Every virtual machine has virtual devices that provide the same functionality as physical hardware are more portable, more secure, and easier to manage.

A virtual machine consists of several files that are stored on a storage device. The key files are the configuration file, virtual disk file, NVRAM setting file, and log file. You configure virtual machine settings through the vSphere Web Client, one of the vSphere command-line interfaces (PowerCLI, vCLI) or the vSphere Web Services SDK.

Virtual Machine Files

File Usage Description
.vmx vmname.vmx Virtual machine configuration file
.vmxf vmname.vmxf Additional virtual machine configuration files
.vmdk vmname.vmdk Virtual disk characteristics
-flat.vmdk vmname-flat.vmdk Virtual machine data disk
.nvram vmname.nvram or nvram Virtual machine BIOS or EFI configuration
.vmsd vmname.vmsd Virtual machine snapshots
.vmsn vmname.vmsn Virtual machine snapshot data file
.vswp vmname.vswp Virtual machine swap file
.vmss vmname.vmss Virtual machine suspend file
.log vmware.log Current virtual machine log file
-#.log vmware-#.log (where # is a number starting with 1) Old virtual machine log files

VMX files – a VMX file is the primary configuration file for a virtual machine. When you create a new virtual machine and answer questions about the operating system, disk sizes, and networking, those answers are stored in this file. As you can see from the screenshot below, a VMX file is actually a simple text file that can be edited with Notepad. Example:

config.version = "8"
virtualHW.version = "3"
guestOS = "otherlinux"
displayname = "IPFire"
memsize = "256"
MemAllowAutoScaleDown = "FALSE"
usb.present = "TRUE"
ide0:0.present = "TRUE"
ide0:0.filename = "primaryMaster.vmdk"
#ide1:0.autodetect = "TRUE"
#ide1:0.filename = "auto detect"
#ide1:0.deviceType = "cdrom-raw"
ide1:0.present = "true"
ide1:0.deviceType = "cdrom-image"
ide1:0.filename = "ipfire-2.9.i586-full-core48.iso"
ide1:0.startConnected = "TRUE"
floppy0.present = "FALSE"
sound.present = "FALSE"
ethernet0.present = "TRUE"
ethernet0.addressType = "generated"
ethernet0.connectionType= "nat"
ethernet1.present = "TRUE"
ethernet1.addressType = "generated"
ethernet1.connectionType= "nat"
  • Identify virtual machine DirectPath I/O feature

DirectPath I/O allows virtual machine access to physical PCI functions on platforms with an I/O Memory Management Unit.

The following features are unavailable for virtual machines configured with DirectPath:

■ Hot adding and removing of virtual devices
■ Suspend and resume
■ Record and replay
■ Fault tolerance
■ High availability
■ DRS (limited availability. The virtual machine can be part of a cluster, but cannot migrate across hosts)
■ Snapshots

The following features are only available for virtual machines configured with DirectPath I/O on Cisco Unified Computing Systems (UCS) through Cisco Virtual Machine Fabric Extender (VM-FEX) distributed switches.

■ vMotion
■ Hot adding and removing of virtual devices
■ Suspend and resume
■ High availability
■ DRS
■ Snapshots

Enable DirectPath I/O with vMotion on a Virtual Machine
You can enable DirectPath I/O with vMotion for virtual machines in a datacenter on a Cisco UCS system that has at least one supported Cisco UCS Virtual Machine Fabric Extender (VM-FEX) distributed switch.

Prerequisites

1. Enable high performance network I/O on at least one Cisco UCS port profile on a supported Cisco VM-FEX distributed switch. For supported switches and switch configuration, see Cisco’s documentation at http://www.cisco.com/go/unifiedcomputing/b-series-doc.

2. Launch the vSphere Client and log in to a vCenter Server system.

3. Power off the virtual machine.

Procedure
1. Log in to the vSphere Client and select the VMs and Templates inventory view.
2. Right-click the virtual machine to modify and click Edit Settings.
3. On the Resources tab, select Memory.
4. Select Unlimited.
5. On the Hardware tab, select the network adapter to configure as a passthrough device.
6. Select a port profile with high performance enabled from the network label drop-down menu, and click OK.
7. Power on the virtual machine.

After the virtual machine is powered on, DirectPath I/O appears as Active on the Hardware tab of the virtual machine properties dialog box.

DirectPath I/O vs SR-IOV
SR-IOV offers performance benefits and tradeoffs similar to those of DirectPath I/O. DirectPath I/O and SR-IOV have similar functionality but you use them to accomplish different things.

SR-IOV is beneficial in workloads with very high packet rates or very low latency requirements. Like DirectPath I/O, SR-IOV is not compatible with certain core virtualization features, such as vMotion. SR-IOV does, however, allow for a single physical device to be shared amongst multiple guests.

With DirectPath I/O you can map only one physical function to one virtual machine. SR-IOV lets you share a single physical device, allowing multiple virtual machines to connect directly to the physical function.

  • Enable/Disable Advanced virtual machine settings

Edit Configuration File Parameters
You can change or add virtual machine configuration parameters when instructed by a VMware technical support representative, or if you see VMware documentation that instructs you to add or change a parameter to fix a problem with your system.

Prerequisites

Verify that you have the following privileges:

Virtual machine.Configuration.Advanced on the destination folder or datacenter, if you are configuring advanced virtual machine settings.

Procedure
1. Right-click a virtual machine in the inventory and select Edit Settings.
2. Click the VM Options tab and expand Advanced.
3. Click Edit Configuration.
4. (Optional) To add a parameter, click Add Row and type a name and value for the parameter.
5. (Optional) To change a parameter, type a new value in the Value text box for that parameter.
6. Click OK.

Disable Virtual Machine Acceleration

You might find that when you install or run software in a virtual machine, the virtual machine appears to stop responding. The problem occurs early in the program’s execution. You can get past the problem by temporarily disabling acceleration in the virtual machine.

This setting slows down virtual machine performance, so use it only for getting past the problem with running the program. After the program stops encountering problems, deselect Disable acceleration. You might be able to run the program with acceleration.

You can enable and disable acceleration when the virtual machine is running.

Procedure

1  Right-click a virtual machine in the inventory and select Edit Settings.
2  Click the VM Options tab and expand Advanced.
3  Click VM Options and expand Advanced.
4  Select Disable acceleration.
5  Click OK.
You should be able to install or run the software successfully.

Enable Virtual Machine Logging

You can enable logging to collect log files to help troubleshoot problems with your virtual machine.

ESXi hosts store virtual machine log files in the same directory as the virtual machine’s configuration files. By default, the log file name is vmware.log. Archived log files are stored as vmware-n.log, where n is a number in sequential order beginning with 1.

Prerequisites

Required privilege: Virtual machine.Configuration.Settings
Procedure

1  Right-click a virtual machine in the inventory and select Edit Settings.
2  Click the VM Options tab and expand Advanced.
3  In the Settings row, select Enable logging and click OK.
You can view and compare log files in the same storage location as the virtual machine configuration files.

Configure Virtual Machine Debugging and Statistics

You can run a virtual machine so that it collects additional debugging information that is helpful to VMware technical support in resolving issues.

Prerequisites

Power off the virtual machine.

Procedure

1  Right-click a virtual machine in the inventory and select Edit Settings.
2  Click the VM Options tab and expand Advanced.
3  Select a debugging and statistics option from the drop-down menu.

  • Run normally
  • Record Debugging Information
  • Record Statistics
  • Record Statistics and Debugging Information

The number of debugging and statistics options available depends on the host software type and version. On some hosts, some options are not available.

4 Click OK.
Change the Swap File Location

When a virtual machine is powered on, the system creates a VMkernel swap file to serve as a backing store for the virtual machine’s RAM contents. You can accept the default swap file location or save the file to a different location. By default, the swap file is stored in the same location as the virtual machine’s configuration file.

Procedure

  1. Right-click a virtual machine in the inventory and select Edit Settings.
  2. Click the VM Options tab and expand Advanced.
  3. Select a swap file location option.
  4. Click OK.

table-advance

Edit Configuration File Parameters

You can change or add virtual machine configuration parameters when instructed by a VMware technical support representative, or if you see VMware documentation that instructs you to add or change a parameter to fix a problem with your system.

IMPORTANT Changing or adding parameters when a system does not have problems might lead to decreased system performance and instability.

The following conditions apply:

  • To change a parameter, you change the existing value for the keyword/value pair. For example, if you start with the keyword/value pair, keyword/value, and change it to keyword/value2, the result is keyword=value2.
  • You cannot delete a configuration parameter entry.

CAUTION You must assign a value to configuration parameter keywords. If you do not assign a value, the keyword can return a value of 0, false, or disable, which can result in a virtual machine that cannot power on.

Procedure

1  Right-click a virtual machine in the inventory and select Edit Settings.
2  Click the VM Options tab and expand Advanced.
3  Click Edit Configuration.
4  (Optional) To add a parameter, click Add Row and type a name and value for the parameter.
5  (Optional) To change a parameter, type a new value in the Value text box for that parameter.
6  Click OK.

Enabling the latency-sensitivity feature for a given VM.

The latency-sensitivity feature is applied per VM, and thus a vSphere host can run a mix of normal VMs and VMs with this feature enabled. To enable the latency sensitivity for a given VM from the UI, access the Advanced Settings from the VM Options tab in the VM’s Edit Settings pop-up window and select High for the Latency Sensitivity

enable-latency-sensitivity

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