When installing or upgrading to ESXi 5.5, ensure that the host meets these minimum hardware configurations supported by ESXi 5.5:
- Your hardware is compliant on the VMware Compatibility Guide. This includes:
- System compatibility
- I/O compatibility (Network and HBA cards)
- Storage compatibility
- Backup software compatibility
- You have a 64-bit processor. VMware ESXi 5.5 only installs and runs on servers with 64-bit x86 CPUs. It also only supports LAHF and SAHF CPU instructions.
- You have an ESXi 5.5 host machine with at least two cores.
- The NX/XD bit is enabled for the CPU in the BIOS.
- Your processor is supported. ESXi supports a broad range of x64 multicore processors. For a complete list of supported processors, see the VMware Compatibility Guide.
- You have 4GB RAM. This is the minimum required to install ESXi 5.5. Provide at least 8GB of RAM to take full advantage of ESXi features and run virtual machines in typical production environments.
- Support for hardware virtualization (Intel VT-x or AMD RVI) is enabled on x64 CPUs (to support 64-bit virtual machines). For a complete list of operating systems supported with ESXi, see the VMware Compatibility Guide. Hosts running virtual machines with 64-bit guest operating systems have these hardware requirements:
- For AMD Opteron-based systems, the processors must be Opteron Rev E or later.
- For Intel Xeon-based systems, the processors must include support for Intel Virtualization Technology (VT). Many servers that include CPUs with VT support might have VT disabled by default, so you must enable VT manually. If your CPUs support VT , but you do not see this option in the BIOS, contact your vendor to request a BIOS version that lets you enable VT support.
Note: To determine whether your server has 64-bit VMware support, download the CPU Identification Utility from the VMware Website.
- You have one or more Gigabit or 10GB Ethernet controllers. For a list of supported network adapter models, see the VMware Compatibility Guide.
- You have Storage controllers with any combination of one or more of:
- Basic SCSI controllers. Adaptec Ultra-160 or Ultra-320, LSI Logic Fusion-MPT, or most NCR/Symbios SCSI.
- RAID controllers. Dell PERC (Adaptec RAID or LSI MegaRAID), HP Smart Array RAID, or IBM (Adaptec) ServeRAID controllers.
- You have SCSI disk or a local, non-network, RAID LUN with unpartitioned space for the virtual machines.
- For Serial ATA (SATA), a disk connected through supported SAS controllers or supported on-board SATA controllers. SATA disks are considered to be remote, not local. These disks are not used as a scratch partition by default because they are seen as remote.
Note: You cannot connect a SATA CD-ROM device to a virtual machine on an ESXi 5.5 host. To use the SATA CD-ROM device, you must use IDE emulation mode. - You are using a supported storage system. ESXi 5.5 supports installing on and booting from these storage systems:
- SATA disk drives. SATA disk drives connected behind supported SAS controllers or supported on-board SATA controllers.
- LSI1068E (LSISAS3442E)
- LSI1068 (SAS 5)
- IBM ServeRAID 8K SAS controller
- Smart Array P400/256 controller
- Dell PERC 5.0.1 controller
- SATA disk drives. Supported on-board SATA include:
- Intel ICH9
- NVIDIA MCP55
- ServerWorks HT1000
- SATA disk drives. SATA disk drives connected behind supported SAS controllers or supported on-board SATA controllers.
- You have Serial Attached SCSI (SAS) disk drives supported for installing ESXi 5.5 and for storing virtual machines on VMFS partitions.
- You have dedicated SAN disk on Fibre Channel or iSCSI.
- You have USB devices that are supported for installing ESXi .
- You can install and boot ESXi from an FCoE LUN using VMware software FCoE adapters and network adapters with FCoE offload capabilities. See the vSphere Storage documentation for information about installing and booting ESXi with software FCoE.
ESXi booting requirements
vSphere 5.5 supports booting ESXi hosts from the Unified Extensible Firmware Interface (UEFI). With UEFI you can boot systems from hard drives, CD-ROM drives, or USB media. Network booting or provisioning with VMware Auto Deploy requires the legacy BIOS firmware and is not available with UEFI.
ESXi can boot from a disk larger than 2TB, provided that the system firmware and the firmware on any add-in card that you are using support it. For more information, see the vendor documentation.
Note: Changing the boot type from legacy BIOS to UEFI after you install ESXi 5.5 may cause the host to fail to boot. In this case, the host reports an error similar to:
Not a VMware boot bank. Changing the host boot type between legacy BIOS and UEFI is not supported after you install ESXi 5.5.
Storage requirements
ESXi 5.5 has these storage requirements:
- Installing ESXi 5.5 requires a boot device that is minimum 1GB in size. When booting from a local disk or SAN/iSCSI LUN, a 5.2GB disk is required to allow the creation of the VMFS volume and a 4GB scratch partition on the boot device. If a smaller disk or LUN is used, the installer attempts to allocate a scratch region on a separate local disk. If a local disk cannot be found, the scratch partition (/scratch) is located on the ESXi host ramdisk, linked to /tmp/scratch. You can reconfigure /scratch to use a separate disk or LUN. For best performance and memory optimization, VMware recommends that you do not leave /scratch on the ESXi host ramdisk.
- To reconfigure /scratch, see Set the Scratch Partition from the vSphere Client in the vSphere Installation and Setup Guide.
- Due to the I/O sensitivity of USB and SD devices, the installer does not create a scratch partition on these devices. As such, there is no tangible benefit to using large USB/SD devices as ESXi uses only the first 1GB. When installing on USB or SD devices, the installer attempts to allocate a scratch region on an available local disk or datastore. If no local disk or datastore is found, /scratch is placed on the ramdisk. You should reconfigure /scratch to use a persistent datastore following the installation.
- In Auto Deploy installations, the installer attempts to allocate a scratch region on an available local disk or datastore. If no local disk or datastore is found /scratch is placed on ramdisk. You should reconfigure /scratch to use a persistent datastore following the installation.
- For environments that boot from a SAN or use Auto Deploy, it is not necessary to allocate a separate LUN for each ESXi host. You can co-locate the scratch regions for many ESXi hosts onto a single LUN. The number of hosts assigned to any single LUN should be weighed against the LUN size and the I/O behavior of the virtual machines.
Best practices for upgrading or migrating ESXi hosts
For a successful upgrade or migration, follow these best practices:
- If your vSphere system includes VMware solutions or plug-ins, ensure that they are compatible with the vCenter Server version that you are upgrading to. For more information, see the VMware Product Interoperability Matrix.
- Read Preparing to Upgrade Hosts in the vSphere Upgrade Guide to understand the changes in configuration and partitioning between ESX/ESXi 4.x and ESXi 5.x, the upgrade and migration scenarios that are supported, and the options and tools available to perform the upgrade or migration.
- Read the VMware vSphere Release Notes for known installation issues.
- If your vSphere installation is in a VMware View environment, see Upgrading vSphere Components Separately in a Horizon View Environment in the vSphere Upgrade Guide.
To prepare your system for the upgrade:
- Ensure that your current ESX/ESXi version is supported for migration or upgrade. For more information, see Supported Upgrades to ESXi 5.5 in the vSphere Upgrade Guide.
- Ensure that your system hardware complies with above ESXi requirements. For more information, see the System Requirementssection in the vSphere Upgrade Guide and the VMware Compatibility Guide. Check for system compatibility, I/O compatibility (network and HBA cards), storage compatibility, and backup software compatibility.
- Ensure that sufficient disk space is available on the host for the upgrade or migration. Migrating from ESX 4.x to ESXi 5.x requires 50MB of free space on your VMFS datastore.
- If a SAN is connected to the host, detach the fibre before continuing with the upgrade or migration. Do not disable HBA cards in the BIOS.
Note: This step does not apply to ESX hosts that boot from the SAN and have the Service Console on the SAN LUNs. You can disconnect LUNs that contain the VMFS datastore and do not contain the Service Console.
- VMware strongly recommends that you back up your host before performing an upgrade or migration, so that, if the upgrade fails, you can restore your host.
Important: After upgrading or migrating your host to ESXi 5.x, you cannot roll back to the earlier version. - Depending on the upgrade or migration method you choose, you may have to migrate or power off all virtual machines on the host.
- After the upgrade or migration, test the system to ensure that the upgrade or migration completed successfully.
- Reapply your host licenses. For more information, see the Reapplying Licenses After Upgrading to ESXi 5.5 section in the vSphereUpgrade Guide.
- Consider setting up a syslog server for remote logging, to ensure sufficient disk storage for log files. Setting up logging on a remote host is especially important for hosts with limited local storage. Optionally, you can install the vSphere Syslog Collector to collect logs from all hosts. See Providing Sufficient Space for System Logging. For information about setting up and configuring syslog and a syslog server, setting up syslog from the host profiles interface, and installing vSphere Syslog Collector, see the vSphere Installation and Setup Guide.
- If the upgrade or migration was unsuccessful, you can restore your host if you have a valid backup.