vsphere-esxi-vcenter-server-55-storage-guide

Configuring Fibre Channel Storage 4When you use ESXi systems with SAN storage, specific hardware and system requirements exist.This chapter includes the following topics:• “ESXi Fibre Channel SAN Requirements,” on page 39• “Installation and Setup Steps,” on page 40• “N-Port ID Virtualization,” on page 41ESXi Fibre Channel SAN RequirementsIn preparation for configuring your SAN and setting up your ESXi system to use SAN storage, review therequirements and recommendations.• Make sure that the SAN storage hardware and firmware combinations you use are supported inconjunction with ESXi systems. For an up-to-date list, see the vSphere Compatibility Guide.• Configure your system to have only one VMFS volume per LUN.• Unless you are using diskless servers, do not set up the diagnostic partition on a SAN LUN.In the case of diskless servers that boot from a SAN, a shared diagnostic partition is appropriate.• Use RDMs to access raw disks. For information, see Chapter 17, “Raw Device Mapping,” on page 155.• For multipathing to work properly, each LUN must present the same LUN ID number to all ESXi hosts.• Make sure the storage device driver specifies a large enough queue. You can set the queue depth for thephysical HBA during system setup. For information on changing queue depth for HBAs and virtualmachines, see the vSphere Troubleshooting documentation.• On virtual machines running Microsoft Windows, increase the value of the SCSI TimeoutValueparameter to 60. This increase allows Windows to better tolerate delayed I/O resulting from pathfailover. For information, see “Set Timeout on Windows Guest OS,” on page 219.ESXi Fibre Channel SAN RestrictionsWhen you use ESXi with a SAN, certain restrictions apply.• ESXi does not support FC connected tape devices.• You cannot use multipathing software inside a virtual machine to perform I/O load balancing to asingle physical LUN. However, when your Microsoft Windows virtual machine uses dynamic disks,this restriction does not apply. For information about configuring dynamic disks, see “Set Up DynamicDisk Mirroring,” on page 148.VMware, Inc. 39