What is LUN?

What is LUN?  Logical Unit Number is a unique identifier used on a SCSI bus that enables it to differentiate between up to eight separate devices (each of which is a logical unit).On a SCSI parallel bus (a type of inter-connect used to connect SAN Storage devices, it is different from Fibre Channel) it is possible to have different devices, and each one is given an address called a logical unit number (LUN). The LUN on a SCSI parallel bus is actually used to electrically address the various devices. The concept of a LUN has been adapted to Fibre Channel devices to allow multiple SCSI devices to appear on a single Fibre Channel connection.

The LUN is required to be unique among all devices that are visible to each other. When a LUN is assigned to a server, it acts as a physical disk drive for the server. The server can perform read and write operations on it. Storage Administrators can assign access and control privileges on a per-LUN basis. The different types of LUN supported by the storage subsystem are: Simple, Spanned, Striped, Mirrored, and Striped with Parity.

In the SAN Storage environment, the definition is much broader since it is possible, although usually not desirable, that all devices attached to a SAN can see each other. A RAID controller that simulates multiple SCSI devices with different LUN’s is said to have multi-LUN support. This allows a single RAID controller to present its storage as many smaller devices. LUNs represent a logical abstraction or, virtualization layer between the physical disk device/volume and the applications.

The term virtualization has been used to mean many different things; thus, the virtualization police may or may not agree to a LUN being a layer of virtualization. A LUN can be used to present a larger or smaller view of the disk storage to the server. In Windows server, the Storage administrator will have to do the DISKPART in order to “activate” the drive.

Importing Virtual Machines and System Images from Other Formats

To accompany Workstation release version 5.0, VMware introduced the VMware Virtual Machine Importer, a separate downloadable application for Windows hosts that creates a new VMware virtual machine from a Microsoft Virtual PC or Virtual Server virtual machine. In Workstation release version 5.5, the importer is incorporated into the Workstation program for Windows hosts, and enhanced with the ability to create VMware virtual machines from system images created with Symantec LiveState Recovery.
If you have upgraded Workstation to version 5.5, you no longer need the standalone VMware Virtual Machine Importer application: you can import virtual machines and system images directly from Workstation, as described in the following sections.
If you have not upgraded your Workstation program to version 5.5, the standalone VMware Virtual Machine Importer is available as a download from the VMware Web site at www.vmware.com/download/">www.vmware.com/download/
. You can download the user's manual that accompanies the standalone importer at
www.vmware.com/pdf/vm_importer_manual.pdf">www.vmware.com/pdf/vm_importer_manual.pdf. Note: Although Workstation version 5.5 includes the importer, the standalone VMware Virtual Machine Importer v1.5 is compatible with Workstation 5.5. You can install both programs on the same machine. The Windows control panel Add or Remove Programs will contain entries for VMware Virtual Machine Importer 1.5 and Workstation 5.5. The Virtual Machine Importer files will remain until you uninstall both the importer and Workstation applications.

Caution: The standalone VMware Virtual Machine Importer v1.0 is not compatible with Workstation 5.5. If you currently have Workstation 5.5 installed, do not attempt to install VMware Virtual Machine Importer v1.0. The version 1.0 importer cannot be installed over Workstation 5.5. Attempting this installation will damage the Workstation installation and disable the import capability built into Workstation 5.5.

Virtual Machine Importer: Overview

The VMware Virtual Machine Importer allows you to import virtual machines from Microsoft® Virtual Server and Virtual PC, and Symantec® LiveState Recovery system images to the following VMware platforms:

Workstation 5.0

Legacy Virtual Machines (for example, virtual machines compatible with Workstation 4.x, GSX Server 3.x, ESX Server 2.x, and ACE 1.x)

The importer is a wizard that outputs a completely new VMware virtual machine based on the input virtual machine or system image. The newly-migrated VMware virtual machine retains the configuration of the original virtual machine or image.
The migration process is non-destructive, so you can continue to use the original virtual machine with Virtual PC, or the original system image with LiveState Recovery. However, if you plan to run a new VMware virtual machine on the same network as the original Virtual PC virtual machine, you must modify the network name and IP address on one of the virtual machines, so the original and new virtual machines can coexist properly.

Benefits of the Importer

The importer lets you convert existing Virtual PC virtual machines and LiveState Recovery system images to VMware virtual machines, allowing you to:

Avoid reinstalling operating systems and applications for system configurations you use often.

Overcome legacy migration barriers — certain legacy systems may be impossible to recreate through reinstallation.

Setting Up a New Virtual Machine in VMware Workstation 5.5

Setting Up a New Virtual Machine

The New Virtual Machine Wizard guides you through the key steps for setting up a new virtual machine, helping you set various options and parameters. You can then use the virtual machine settings editor (VM > Settings) if you need to make any changes to your virtual machine's setup.
By default, the new virtual machine uses an IDE disk for Windows 95, Windows 98, Windows Me, Windows XP, Windows Server 2003, NetWare and FreeBSD guests. The default for other guest operating systems is a SCSI disk.
Follow these steps to create a virtual machine using a virtual disk.

1. Start VMware Workstation.

Windows hosts: Double-click the VMware Workstation icon on your desktop or use the Start menu (Start > Programs > VMware > VMware Workstation).

Linux hosts: In a terminal window, enter the command

vmware &

Note: On Linux hosts, the Workstation installer adds an entry to the Start menu for VMware Workstation. However, this menu entry is located in different submenus, depending on your Linux distribution. For example:

SUSE Linux 9.1 — Start > System > More Programs > VMware Workstation

Red Hat Enterprise Linux AS/WS Release 3 — Start > System Tools > More System Tools > VMware Workstation

2. If this is the first time you have launched VMware Workstation and you did not enter the serial number when you installed the product (an option available on a Windows host), you are prompted to enter it. The serial number is on the registration card in your package or in the email message confirming your electronic distribution order. Enter your serial number and click OK.

The serial number you enter is saved and VMware Workstation does not ask you for it again. For your convenience, VMware Workstation automatically sends the serial number to the VMware Web site when you use certain Web links built into the product (for example, Help > VMware on the Web > Register Now! and Help > VMware on the Web > Request Support). This allows us to direct you to the correct Web page to register and get support for your product.

3. Start the New Virtual Machine Wizard.

When you start VMware Workstation, you can open an existing virtual machine or create a new one. Choose File > New > Virtual Machine to begin creating your virtual machine.

4. The New Virtual Machine Wizard presents you with a series of screens that you navigate using the Next and Prev buttons at the bottom of each screen. At each screen, follow the instructions, then click Next to proceed to the next screen.

5. Select the method you want to use for configuring your virtual machine.

If you select Typical, the wizard prompts you to specify or accept defaults for the following choices:

The guest operating system

The virtual machine name and the location of the virtual machine's files

The network connection type

Whether to allocate all the space for a virtual disk at the time you create it

Whether to split a virtual disk into 2GB files

If you select Custom, you also can specify how to set up your disk — create a new virtual disk, use an existing virtual disk or use a physical disk — and specify the settings needed for the type of disk you select. There is also an option to create a legacy virtual disk for use in environments with other VMware products.

Select Custom if you want to

Make a legacy virtual machine that is compatible with Workstation 4.x, GSX Server 3.x, ESX Server 2.x and VMware ACE 1.x.

Store your virtual disk's files in a particular location

Use an IDE virtual disk for a guest operating system that would otherwise have a SCSI virtual disk created by default

Use a physical disk rather than a virtual disk (for expert users)

Set memory options that are different from the defaults

Assign more than one virtual processor to the virtual machine

6. If you selected Typical as your configuration path, skip to step 7.

If you selected Custom as your configuration path, you may create a virtual machine that fully supports all Workstation 5 features or a legacy virtual machine compatible with specific VMware products.

This screen asks whether you want to create a Workstation 5 virtual machine or a legacy virtual machine. See Legacy Virtual Disks for more information.

7. Select a guest operating system.

This screen asks which operating system you plan to install in the virtual machine. Select both an operating system and a version. The New Virtual Machine Wizard uses this information to

Select appropriate default values, such as the amount of memory needed

Name files associated with the virtual machine

Adjust settings for optimal performance

Work around special behaviors and bugs within a guest operating system

If the operating system you plan to use is not listed, select Other for both guest operating system and version.

Note: Workstation supports 64-bit guest operating systems only in Workstation versions 5.5 and later, and only on host machines with supported processors. For the list of processors Workstation supports for 64-bit guest operating systems, see Support for 64-Bit Guest Operating Systems.

Caution: Do not attempt to install a 64-bit operating system after selecting a 32-bit guest operating system type here.

The remaining steps assume you plan to install a Windows XP Professional guest operating system. You can find detailed installation notes for this and other guest operating systems in the VMware Guest Operating System Installation Guide, available from the VMware Web site or from the Help menu.

8. Select a name and folder for the virtual machine.

The name specified here is used if you add this virtual machine to the VMware Workstation Favorites list. This name is also used as the name of the folder where the files associated with this virtual machine are stored.

Each virtual machine should have its own folder. All associated files, such as the configuration file and the disk file, are placed in this folder.

Windows hosts: On Windows 2000, Windows XP and Windows Server 2003, the default folder for this Windows XP Professional virtual machine is C:\Documents and Settings\<username>\My Documents\My Virtual Machines\Windows XP Professional. On Windows NT, the default folder is C:\WINNT\Profiles\<username>\Personal\My Virtual Machines\Windows XP Professional.

Linux hosts: The default location for this Windows XP Professional virtual machine is <homedir>/vmware/winXPPro, where <homedir> is the home directory of the user who is currently logged on.

Virtual machine performance may be slower if your virtual hard disk is on a network drive. For best performance, be sure the virtual machine's folder is on a local drive. However, if other users need to access this virtual machine, you should consider placing the virtual machine files in a location that is accessible to them. For more information, see Sharing Virtual Machines with Other Users.

9. Specify the number of processors for the virtual machine. The setting Two is supported only for host machines with at least two logical processors.

Note: The following are all considered to have two logical processors:

A single-processor host with hyperthreading enabled

A single-processor host with a dual-core CPU

A multiprocessor host with two CPUs, neither of which are dual-core or have hyperthreading enabled

If the host does not have at least two logical processors, assigning two virtual processors is neither supported nor recommended: a warning message will appear. You can disregard this message and assign two virtual processors to the virtual machine, but, once you have finished creating the virtual machine, you will not be able to power it on unless you move it to a host machine with at least two logical processors. For more about Workstation support for virtual Symmetric Multiprocessing (SMP), see Using Two-Way Virtual Symmetric Multiprocessing (Experimental).

10. If you selected Typical as your configuration path, skip to step 11.

If you selected Custom as your configuration path, you may adjust the memory settings or accept the defaults, then click Next to continue.

In most cases, it is best to keep the default memory setting. If you plan to use the virtual machine to run many applications or applications that need high amounts of memory, you may want to use a higher memory setting. For more information, see Virtual Machine Memory Size.

Note: You cannot allocate more than 2GB of memory to a virtual machine if the virtual machine's files are stored on a file system such as FAT32 that does not support files greater than 2GB.

11. Configure the networking capabilities of the virtual machine.

If your host computer is on a network and you have a separate IP address for your virtual machine (or can get one automatically from a DHCP server), select Use bridged networking.

If you do not have a separate IP address for your virtual machine but you want to be able to connect to the Internet, select Use network address translation (NAT). NAT allows you to share files between the virtual machine and the host operating system.

For more details about VMware Workstation networking options, see Configuring a Virtual Network.

12. If you selected Typical as your configuration path, click Finish and the wizard sets up the files needed for your virtual machine.

If you selected Custom as your configuration path, continue with the steps below to configure a disk for your virtual machine.

13. Select the type of SCSI adapter you want to use with the virtual machine.

An IDE and a SCSI adapter are installed in the virtual machine. The IDE adapter is always ATAPI. You can choose a BusLogic or an LSI Logic SCSI adapter. The default for your guest operating system is already selected. All guests except for Windows Server 2003, Red Hat Enterprise Linux 3 and NetWare default to the BusLogic adapter.

The LSI Logic adapter has improved performance and works better with generic SCSI devices. The LSI Logic adapter is also supported by ESX Server 2.0 and higher. Keep this in mind if you plan to migrate the virtual machine to another VMware product.

Your choice of SCSI adapter does not affect your decision to make your virtual disk an IDE or SCSI disk. However, some guest operating systems — such as Windows XP — do not include a driver for the Buslogic or LSI Logic adapter. You must download the driver from the LSI Logic Web site.

Note: Drivers for a Mylex (BusLogic) compatible host bus adapter are not obvious on the LSI Logic Web site. Search the support area for the numeric string in the model number. For example, search for "958" for BT/KT-958 drivers.

See the VMware Guest Operating System Installation Guide for details about the driver and the guest operating system you plan to install in this virtual machine.

14. Select the disk you want to use with the virtual machine.

Select Create a new virtual disk.

Virtual disks are the best choice for most virtual machines. They are quick and easy to set up and can be moved to new locations on the same host computer or to different host computers. By default, virtual disks start as small files on the host computer's hard drive, then expand as needed — up to the size you specify in the next step. The next step also allows you to allocate all the disk space when the virtual disk is created, if you wish.

To use an existing operating system on a physical hard disk (a "raw" disk), read Configuring a Dual-Boot Computer for Use with a Virtual Machine. To install your guest operating system directly on an existing IDE disk partition, read the reference note Installing an Operating System on a Physical Partition from a Virtual Machine.

Note: Physical disk configurations are recommended only for expert users.

Caution: If you are using a Windows Server 2003, Windows XP or Windows 2000 host, see Do Not Use Windows 2000, Windows XP and Windows Server 2003 Dynamic Disks as Physical Disks.

To install the guest operating system on a IDE physical disk, select Existing IDE Disk Partition. To use a SCSI physical disk, add it to the virtual machine later with the virtual machine settings editor. Booting from a SCSI physical disk is not supported. For a discussion of some of the issues involved in using a SCSI physical disk, see Configuring Dual- or Multiple-Boot SCSI Systems to Run with VMware Workstation on a Linux Host.

15. Select whether to create an IDE or SCSI disk.

The wizard recommends the best choice based on the guest operating system you selected. All Linux distributions you can select in the wizard use SCSI virtual disks by default, as do Windows NT, Windows 2000, and Windows Vista. All Windows operating systems except Windows NT, Windows 2000, and Windows Vista use IDE virtual disks by default; NetWare, FreeBSD, MS-DOS and other guests default to IDE virtual disks.

16. Specify the capacity of the virtual disk.

Enter the size of the virtual disk that you wish to create.

You can set a size between 0.1GB and 950 GB for a SCSI virtual disk.

The option Allocate all disk space now gives somewhat better performance for your virtual machine. If you do not select Allocate all disk space now, the virtual disk's files start small and grow as needed, but they can never grow larger than the size you set here.

Note: Allocate all disk space now is a time-consuming operation that cannot be cancelled, and requires as much physical disk space as you specify for the virtual disk.

Select the option Split disk into 2GB files if your virtual disk is stored on a file system that does not support files larger than 2GB.

17. Specify the location of the virtual disk's files.

18. Click Finish.

The wizard sets up the files needed for your virtual machine.