VMware 4817V62 Administration Guide - Page 117

Chapter 11 Creating Virtual Machines n Disks on Paravirtual SCSI adapters might not experience performance gains if they have snapshots or if memory on the ESX host is over committed. n If you upgrade from RHEL 5 to an unsupported kernel, you might not be able to access data on the disks attached to a Paravirtual SCSI adapter. To regain access to such disks, run the VMware Tools configuration (vmware-config-tools.pl) with kernel-version parameter and pass the kernel version after the kernel is upgraded and before the virtual machine is rebooted. Run uname -r to determine the version of the running kernel. Select a SCSI Adapter The Select SCSI Controller Type page enables you to select one of the following types of SCSI controllers. The choice of SCSI controller does not affect whether your virtual disk is an IDE or SCSI disk. The IDE adapter is always ATAPI. The default for your guest operating system is already selected. Older guest operating systems default to the BusLogic adapter. If you create an LSI Logic virtual machine and add a virtual disk that uses BusLogic adapters, the virtual machine boots from the BusLogic adapters disk. LSI Logic SAS is available only for virtual machines with hardware version 7. Disks with snapshots might not experience performance gains when used on LSI Logic SAS and LSI Logic Parallel adapters. Procedure u Choose one of the following SCSI controller types: n BusLogic Parallel n LSI Logic SAS n LSI Logic Parallel n VMware Paravirtual Selecting a Virtual Disk Type A virtual disk comprises one or more files on the file system that appear as a single hard disk to the guest operating system. These disks are portable among hosts. You can select among the following options: n "Create a Virtual Disk," on page 118 n "Use an Existing Virtual Disk," on page 118 n "Create Raw Device Mappings," on page 119 n "Do Not Create a Disk," on page 119 VMware, Inc. 117