GSX Server uses description files to control access to each raw IDE device on the system. These description files contain access privilege information that controls a virtual machine's access to certain partitions on the disks. This mechanism prevents users from accidentally running the host operating system again as a guest or running a guest operating system that the virtual machine was not configured to use. The description file also prevents accidental corruption of physical disk partitions by badly behaved operating systems or applications.

Use the New Virtual Machine Wizard or the VMware Management Interface to configure GSX Server to use existing physical disk partitions. The wizard guides you though creating a configuration for a new virtual machine including configuring the physical disk description files. Typically, you rerun the wizard to create a separate configuration for each guest operating system installed on a raw partition.

If a boot manager is installed on the computer system, the boot manager runs inside the virtual machine and presents you with the choice of guest operating systems to run. You must manually choose the guest operating system that this configuration was intended to run.

There is a potential problem with GSX Server on Windows hosts when you boot an operating system from an existing partition. If the Windows host's partition uses a FAT file system, the guest operating system (for example, Windows 98 or Windows 95) sees this partition at boot time and attempts to fix the file system on that partition. This causes serious problems, because the host operating system is actively using that partition.

If you use an advanced boot manager such as BootMagic (PowerQuest) or System Commander (V Communications), it solves this problem by changing the partition type to "unknown." If you are already using such an advanced boot manager to dual boot, the boot manager's partition marking scheme works fine with GSX Server.

However, if you are not using an advanced boot manager for dual booting, the configuration process described below hides partitions that do not belong to the guest operating system. When physical disk partition hiding is enabled, all read-only partitions are mapped to "unknown." Also, all updates to the master boot record are intercepted and not written to the actual master boot record.

If your host is running Windows 2000, Windows XP or Windows Server 2003 and is using dynamic disks, see Do Not Use Windows 2000, Windows XP and Windows Server 2003 Dynamic Disks as Physical Disks.

If you are using the LILO boot loader and try to boot a virtual machine from an existing raw partition, you may see L 01 01 01 01 01 01 ... instead of a LILO: prompt. This can happen regardless of the host operating system. As part of booting a physical PC or a virtual machine, the BIOS passes control to code located in the master boot record (MBR) of the boot device. LILO begins running from the MBR, and in order to finish running correctly, it needs access to the native Linux partition where the rest of LILO is located — usually the partition with the /boot directory. If LILO can't access the rest of itself, an error message like the one above appears.

To avoid the problem, follow the configuration steps below and be sure to select the native Linux partition where the rest of LILO is located. The next time the virtual machine tries to boot, the LILO code in the MBR should be able to access the rest of LILO and display the normal LILO: prompt.

Use the following steps to run a guest operating system from a physical disk.

1. If you are running a Windows guest operating system, read Setting Up Hardware Profiles in Virtual Machines. You should boot the guest operating system natively on the computer and create a hardware profile for the virtual machine before proceeding.

2. Create a separate configuration for each guest operating system.

To configure a virtual machine to run from a physical disk or one of its partitions, start the New Virtual Machine Wizard (File > New Virtual Machine) and select Custom.

3. When you reach the Select a Disk step, select Use a physical disk.

4. Complete the wizard steps, specifying the appropriate disk or partition to use for this virtual machine.

5. To run multiple guest operating systems from different physical disk partitions, unmap these partitions on the host.

Use Disk Management (Start > Settings > Control Panel > Administrative Tools > Computer Management > Storage > Disk Management). Select the partition you want to unmap, then from the Action menu select All Tasks > Change Drive Letter and Path. Click the Remove button.

6. Use the virtual machine settings editor (VM > Settings) if you want to change any configuration options from the wizard defaults — for example, to change the amount of memory allocated to the guest operating system.

7. If you have multiple IDE drives configured on a system, the VMware BIOS normally attempts to boot them in this sequence:

a. Primary master

b. Primary slave

c. Secondary master

d. Secondary slave

If you have multiple SCSI drives configured on a system, the VMware BIOS normally attempts to boot them in the order of the SCSI device number.

If you have both SCSI and IDE drives configured, the VMware BIOS normally attempts to boot SCSI drives followed by IDE drives, in the order listed above.

The boot sequence can be changed in the Boot menu of the virtual machine's Phoenix BIOS. After powering on the virtual machine, press F2 during the BIOS boot in the virtual machine to enter the BIOS setup menu.

8. Power on the virtual machine. Click the Power On button. The virtual machine starts, runs the Phoenix BIOS, then boots from the master boot record (MBR).

Choose the target operating system from the list of options offered by the boot manager.

9. Remember that your virtual machine hardware environment, which the guest operating system is about to run in for the first time, probably differs significantly from the physical hardware of your host computer.

For Windows guest operating systems, Plug and Play reconfigures Windows. Set up your virtual hardware profile with the devices found and configured by Plug and Play. See Setting Up Hardware Profiles in Virtual Machines for more information.

10. Install VMware Tools in your guest operating system.

1. If you are running a Windows guest operating system, read Setting Up Hardware Profiles in Virtual Machines. You should boot the guest operating system natively on the computer and create a hardware profile for the virtual machine before proceeding.

2. Create a separate configuration for each guest operating system.

3. Check operating system partition mounts. Be sure the existing disk partitions that you plan to configure the virtual machine to use are not mounted by Linux.

4. Set the device group membership or device ownership.

The master physical disk device or devices need to be readable and writable by the user who runs GSX Server. On most distributions, the raw devices, such as /dev/hda (IDE physical disk) and /dev/sda (SCSI physical disk) belong to group ID disk. If this is the case, you can add GSX Server users to the disk group. Another option is to change the owner of the device. Please think carefully about security issues when exploring different options here.

Often, the most convenient approach is to grant GSX Server users access to all /dev/hd[abcd] raw devices that contain operating systems or boot managers and then rely on GSX Server's physical disk configuration files to guard access. This provides boot managers access to configuration files and other files they may need to boot the operating systems. For example, LILO needs to read /boot on a Linux partition to boot a non-Linux operating system that may be on another drive. As noted above, you should consider the security implications of the configuration you choose.

5. If you plan to run a second Linux installation from an existing partition as a guest operating system and your physical computer's /etc/lilo.conf has a memory register statement such as Append= "mem...", you may want to adjust the append memory parameter or create a new entry in LILO for running Linux in a virtual machine.

If the amount of memory configured in lilo.conf exceeds the amount of memory assigned to the virtual machine, the guest operating system is likely to panic when the virtual machine tries to boot the second Linux installation.

You can create another entry in lilo.conf for running Linux in a virtual machine by specifying a different amount of memory than what would normally be recognized when Linux boots directly on the physical machine.

6. To configure a virtual machine to run from a physical disk partition, start the New Virtual Machine Wizard (File > New > New Virtual Machine) and select Custom.

7. When you reach the Select a Disk step, select Use a physical disk.

8. Complete the wizard steps, specifying the appropriate disk or partition to use for this virtual machine.

To safeguard against this problem, be sure the partition you use in the virtual machine is not mounted under the Linux host.

9. Complete the remaining steps in the wizard.

10. If you have multiple IDE drives configured on a system, the VMware BIOS normally attempts to boot them in this sequence:

a. Primary master

b. Primary slave

c. Secondary master

d. Secondary slave

If you have multiple SCSI drives configured on a system, the VMware BIOS normally attempts to boot them in the order of the SCSI device number.

If you have both SCSI and IDE drives configured, the VMware BIOS normally attempts to boot SCSI drives followed by IDE drives, in the order listed above.

You can change the boot sequence using the Boot menu of the virtual machine's Phoenix BIOS. To enter the BIOS setup utility, power on the virtual machine and press F2 as the virtual machine begins to boot.

11. Power on the virtual machine. Click the Power On button. The virtual machine starts, runs the Phoenix BIOS, then boots from the master boot record (MBR).

Choose the target operating system from the list of options offered by the boot manager.

12. Remember that your virtual machine hardware environment, which the guest operating system is about to run in for the first time, probably differs significantly from the physical hardware of your machine.

For Windows guest operating systems, Plug and Play reconfigures Windows. Set up your virtual hardware profile with the devices found and configured by Plug and Play. See Setting Up Hardware Profiles in Virtual Machines for more information.

13. Install VMware Tools in your guest operating system.

Warning: If you take a snapshot while using your physical disk, you must either revert to the snapshot or remove the snapshot before you reboot your guest operating system natively. This is necessary because any changes to sectors on the physical disk that have been modified on the disk invalidate the snapshot for the disk.