1,798
edits
Changes
no edit summary
The guest operating system is selected by family and version. For example, once ''Windows operating system'' has been selected, the specific version must then be selected from the ''Version'' drop-down list. It is important to note that even if a guest operating system is not listed, it does not necessarily mean it will not run within VMware Server 2.0. In fact, it is usually sufficient to select the closest match from the list. In the case of unsupported Linux distributions, identify the kernel version (current versions are 2.4 and 2.6) and whether the operating system is 32-bit or 64-bit, and then make an appropriate selection from the ''Other Linux'' options. For a complete list of officially supported guest operating systems, refer to the [[Officially Supported VMware Server 2.0 Guest Operating Systems]] chapter.
Product compatibility is another issue which needs to be considered during the virtual machine creation process. VMware has, over the years, provided a number of different versions of ''virtual machine hardware''. VMWare Server 2.0 uses version 7 by default for virtual machines, which provides new features such as 8Gb 8GB of memory and up to 10 network adapters per virtual machine. One disadvantage, however, of using version 7 of the virtual machine hardware is that it will not be possible to migrate these virtual machines to VMware environments which use older versions of the virtual machine hardware. For example, a VMware Server 2.0 virtual machine running on virtual machine hardware version 7 will not be able to migrate to a host running VMware Server 1.0 or, for that matter, the current release of most other VMware products. If compatibility is of greater priority than the features offered by virtual machine hardware version 7, then it is best to select version 4 on this screen of the wizard.
== Virtual Machine Memory and CPU Settings ==
Once the name of the virtual machine, and type of guest operating system have been defined, the next screen allows the CPU and memory settings for the virtual machine to be specified. It is on this screen that the virtual machine's share of the physical resources of the host computer are is defined. The values specified here will dependent on a number of factors. Firstly, the settings will to a large extent be governed by the amount of physical memory and CPUs available on the host. Secondly, the resource requirements of any other future or currently running virtual machines on the host must also be taken into consideration. In order to assist in arriving at suitable memory settings, the wizard will display recommended, maximum and minimum sizes based on a number of factors including available host resources and the selected guest operating system.
After memory has been assigned to the virtual machine, the number of CPUs or CPU cores to be made available to the virtual machine may be configured. Once again, the optimal setting will depend on the CPUs available on the host together with the requirements of both the host operating system and any other virtual machines:
Most guest operating systems will require that the virtual machine contain a virtual hard disk on which to store both the operating system itself and applications and user data. In a VMWare Server virtual environment, the hard disks assigned to virtual machines are actually disk image files (with the filename extension ''.vmdk'') that reside on the filesystem of the host much like any other data file. As such, a hard disk can be assigned to a virtual machine either by requesting that a new disk image file be created, or by re-using a disk image file created for another virtual machine (note that particular care should be taken when sharing a virtual disk between two virtual machines).
When creating a new disk image for the virtual machine, it is first necessary to define the size of the disk. Any size may be specified up to a maximum of 950GB. The second step is to specify whether the entire disk image should be created now (pre-allocated), or whether the disk should be created at a minimal size, then enlarged as more space is needed (growable). A ''growable'' disk has the advantage that not all of the disk space is taken form from the host until it is needed, and the creation process is faster (creating a large pre-allocated disk can take a considerable amount of time). The downside of using a ''growable'' disk is that write operations may be slower at the point that the disk needs to be enlarged. In addition, it is also possible to have the disk created as multiple 2GB files instead of as one large contiguous data file. This can be useful on older operating systems where file sizes greater than 2GB are not supported.
In addition, the more advanced ''Disk Mode'' setting needs to be configured. If the disk is defined as ''independent'' then the disk is excluded from any virtual machine snapshots. Independent disks can be either ''persistent'', where any data written to the disk by the guest operating system is retained when the system is powered off, or ''non-persistent'' where any data written to the disk by the guest operating system is discarded when the virtual machine is powered off.
The virtual device node settings allow the disk type to appear to the guest operating system as either an IDE or SCSI disk drive. A recommended default selection is provided based on the guest operating system selected at the start of the wizard, although this may be changed if required.
Finally, the disk write caching policy needs to be defined which essentially defines the point at which new data is written to the virtual disk (as opposed to being cached in memory before being written) by the guest operating system. A choice of two options are is available:
* '''Optimize for safety''' - Data is not cached. Write operations made by the guest operating system are written immediately to the virtual disk image. Reduces risk of data loss in the event of a system failure, but results in slower disk write performance.
Options are also available to add hardware devices not previously addressed during the preceded phases of the configuration, such as parallel and serial ports, sounds cards and passthrough pass-through SCSI devices (which provide the guest operating system with direct access to physical SCSI based devices connected to the host system, including such devices as scanners, disks and tape drives). In the case of the sound adapter, VMware Server will install a virtual device that appears to the guest operating system as a Creative Labs SoundBlaster PCI card.
Serial and Parallel ports can be configured such that they reference a physical port on the host, a file on the host file system or, in the case of serial ports, an operating system pipe which may be connected to another application running on the host.
