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→Hard Disk Configuration
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 as a single file, or whether the disk should be created at a minimal size, then enlarged as more space is needed. Splitting the disk up has the advantage that not all of the disk space is taken form 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 so called ''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 advance ''Disk Mode'' setting needs to be configured. If the disk isdefined 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 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. * '''Optimize for performance''' - Write operations performed by the guest operating system are initially cached prior to being written to the virtual disk. Provides increased write performance at the cost of increased risk of data loss on system failure. [[Image:vmware_server_2_configure_disk.jpg|Configuring a VMware Server 2.0 hard disk]]
