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Enhanced vMotion Compatibility (EVC) processor support (1003212)

Details

Enhanced vMotion Compatibility (EVC) simplifies vMotion compatibility issues across CPU generations. EVC automatically configures server CPUs with Intel FlexMigration or AMD-V Extended Migration technologies to be compatible with older servers.

After EVC is enabled for a cluster in the VirtualCenter inventory, all hosts in that cluster are configured to present identical CPU features and ensure CPU compatibility for vMotion. The features presented by each host are determined by selecting a predefined EVC baseline. VirtualCenter does not permit the addition of hosts that cannot be automatically configured to be compatible with the EVC baseline.

Solution

More recent processor architectures are compatible with EVC. The maximum EVC mode that can be supported by a particular processor is listed in the VMware Compatibility Guide for that processor. To use EVC, you must be running ESX 3.5 Update 2 or higher with VirtualCenter 2.5 Update 2 or higher and have compatible processors in your servers. EVC does not allow for migration with vMotion between Intel and AMD processors.

Note: To search for supported EVC CPU types, refer to the VMware Compatibility Guide and search by EVC Modes.

EVC capabilities of your server are based on two factors:
  1. The version of vCenter Server that manages the host.
  2. The underlying CPU architecture of the host processor.
About the tables in this article:
  • Tables 1.1 and 1.2 list the available EVC baselines and their description.
  • Tables 2.1 and 2.2 describe EVC baselines supported by different vCenter Server versions.
In general, if a processor can support EVC level XN, it can also support levels XN-1 to X0. For example, a processor that supports the Intel® "Sandy Bridge" Generation EVC Baseline has an EVC level of L4. Therefore, it can also support EVC levels L3, L2, L1, and L0. However, it cannot support EVC level L5, which corresponds to the Intel® "Ivy Bridge" Generation. Intel EVC Baselines are listed in Table 1.1.

For AMD processors, there are two different sequences of EVC levels: Levels A0 to A3, which support the first 3 generations of AMD Opteron™ processors, and levels B0 and above, which support AMD Opteron™ Generation 3 and later processors. Note that the AMD Opteron™ Generation 3 (no 3DNow!™) EVC baseline is common to both sequences. For example, an AMD processor that supports the AMD Opteron™ Generation 4 EVC baseline can support the AMD Opteron™ Generation 3 (no 3DNow!™) baseline, but not the AMD Opteron™ Generation 3 baseline. An AMD processor that supports the AMD Opteron™ Generation 3 baseline can support the AMD Opteron™ Generation 3 (no 3DNow!™) baseline, but not the AMD Opteron™ Generation 4 baseline. AMD EVC baselines are listed in Table 1.2.

Table 1.1: Description of Intel EVC Baselines

EVC Level EVC Baseline Description
L0 Intel® "Merom" Gen. (Intel® Xeon® Core™ 2) Applies baseline feature set of Intel® "Merom" Generation (Intel® Xeon® Core™ 2) processors to all hosts in the cluster.
L1 Intel® "Penryn" Gen. (formerly Intel® Xeon® 45nm Core™ 2) Applies baseline feature set of Intel® "Penryn" Generation (Intel® Xeon® 45nm Core™ 2) processors to all hosts in the cluster.
Compared to the Intel® "Merom" Generation EVC mode, this EVC mode exposes additional CPU features including SSE4.1.
L2 Intel® "Nehalem" Gen. (formerly Intel® Xeon® Core™ i7) Applies baseline feature set of Intel® "Nehalem" Generation (Intel® Xeon® Core™ i7) processors to all hosts in the cluster.
Compared to the Intel® "Penryn" Generation EVC mode, this EVC mode exposes additional CPU features including SSE4.2 and POPCOUNT.
L3 Intel® "Westmere" Gen. (formerly Intel® Xeon® 32nm Core™ i7) Applies baseline feature set of Intel® "Westmere" Generation (Intel® Xeon® 32nm Core™ i7) processors to all hosts in the cluster. Compared to the Intel® "Nehalem" Generation mode, this EVC mode exposes additional CPU features including AES and PCLMULQDQ.

Note: Intel® i3/i5 Xeon® Clarkdale Series processors that do not support AESNI and PCLMULQDQ cannot be admitted to EVC modes higher than the Intel® "Nehalem" Generation mode.
L4 Intel® "Sandy Bridge" Generation Applies baseline feature set of Intel® "Sandy Bridge" Generation processors to all hosts in the cluster. Compared to the Intel® "Westmere" Generation mode, this EVC mode exposes additional CPU features including AVX and XSAVE.

Note: Intel® "Sandy Bridge" processors that do not support AESNI and PCLMULQDQ cannot be admitted to EVC modes higher than the Intel® "Nehalem" Generation mode.
L5 Intel® "Ivy Bridge" Generation Applies baseline feature set of Intel® "Ivy Bridge" Generation processors to all hosts in the cluster. Compared to the Intel® "Ivy Bridge" Generation EVC mode, this EVC mode exposes additional CPU features including RDRAND, ENFSTRG, FSGSBASE, SMEP, and F16C.

Note: Some Intel® "Ivy Bridge" processors do not provide the full "Ivy Bridge" feature set. Such processors cannot be admitted to EVC modes higher than the Intel® "Nehalem" Generation mode.

Note: In vCenter Server 5.1 and 5.5, the Intel® "Ivy Bridge" Generation option is only displayed in the Web Client.

Table 1.2: Description of AMD EVC Baselines

EVC Level EVC Baseline Description
A0 AMD Opteron™ Generation 1 Applies baseline feature set of AMD Opteron™ Generation 1 (Rev. E) processors to all hosts in the cluster.
A1 AMD Opteron™ Generation 2 Applies baseline feature set of AMD Opteron™ Generation 2 (Rev. F) processors to all hosts in the cluster.
Compared to the AMD Opteron™ Generation 1 EVC mode, this EVC mode exposes additional CPU features including CPMXCHG16B and RDTSCP.
A3 AMD Opteron™ Generation 3 Applies baseline feature set of AMD Opteron™ Generation 3 (Greyhound) processors to all hosts in the cluster.
Compared to the AMD Opteron™ Generation 2 EVC mode, this EVC mode exposes additional CPU features including SSE4A, MisAlignSSE, POPCOUNT and ABM (LZCNT).

Note: Due to 3DNow!™ support being removed from AMD processors after mid 2010, use AMD Opteron™ Generation 3 (no 3DNow!™) when possible to avoid compatibility issues with future processor generations.
A2, B0 AMD Opteron™ Generation 3 (no 3DNow!™) Applies baseline feature set of AMD Opteron™ Generation 3 (Greyhound) processors, with 3DNow!™ support removed, to all hosts in the cluster.
This mode allows you to prepare clusters containing AMD hosts to accept AMD processors without 3DNow!™ support.
B1 AMD Opteron™ Generation 4 Applies baseline feature set of AMD Opteron™ Generation 4 (Bulldozer) processors to all hosts in the cluster.
Compared to the AMD Opteron™ Generation 3 (no 3DNow!™) EVC mode, this EVC mode exposes additional CPU features including SSSE3, SSE4.1, AES, AVX, XSAVE, XOP, and FMA4.
B2 AMD Opteron™ "Piledriver" Generation Applies baseline feature set of AMD Opteron™ "Piledriver" Generation processors to all hosts in the cluster.
Compared to the AMD Opteron™ Generation 4 EVC mode, this EVC mode exposes additional CPU features including FMA, TBM, BMI1, and F16C.

Note: In vCenter Server 5.1 and 5.5, the AMD Opteron™ "Piledriver" Generation option is only displayed in the Web Client.

It is often the case that an older release of vSphere supports a new processor but not the corresponding new EVC baseline that exposes the maximum guest-visible features of that processor. A newer vSphere release usually supports both the processor and the new EVC baseline. This is because the older release can only support those features of the new processor that are in common with older processors. Therefore, support of an EVC baseline is not identical to the support of the corresponding processor. Tables 2.1 and 2.2 indicate the earliest vSphere release that supports each EVC baseline.

As an example, consider the Intel® “Sandy Bridge” Generation EVC baseline and the Intel® Xeon e5-2400 (a processor based on the Intel® “Sandy Bridge” architecture). The processor is supported by both vSphere 4.1 Update 2 (and later) and vSphere 5.0 (and later). But because vSphere 4.1 update 2 lacks support for advanced “Sandy Bridge” features such as AVX, the Intel® “Sandy Bridge” Generation EVC baseline is only supported starting with the vSphere 5.0 release. However, vSphere 4.1 Update 2 does support lower level EVC baselines on the Intel® Xeon e5-2400, such as Intel® “Westmere” Generation and Intel® “Merom” Generation.

Not all members of a given processor generation can support the same maximum EVC baseline. Either because of BIOS configuration or branding decisions made by OEM or CPU vendors, some members of that generation may lack a feature required to participate at the maximum EVC baseline. For example, some Intel® Xeon i3/i5 Clarkdale processors (based on the Intel “Westmere” processor architecture) do not have AESNI capability, which is required for the Intel “Westmere” Generation EVC baseline. Therefore, these processors cannot support that EVC baseline and must use lower levels of EVC baselines. Another example is where AESNI has been disabled by BIOS in an Intel® Xeon 5600 processor (also based on the Intel “Westmere” processor architecture); as a result, this processor also cannot support the Intel® “Westmere” EVC baseline and must use lower levels of EVC baselines.

The VMware Compatibility Guide always correctly lists the maximum EVC baseline for a processor assuming that no BIOS disablement of features has been enforced. Since disabling of features by BIOS is OEM and customer specific, the guide cannot address these cases.

Table 2.1: AMD EVC Baselines supported in vCenter Server releases

EVC Cluster Baseline
vCenter Server Release AMD Opteron™ Gen. 1 AMD Opteron™ Gen. 2 AMD Opteron™ Gen. 3 AMD Opteron™ Gen. 3 (no 3DNow!™) AMD Opteron™ Gen. 4 AMD Opteron "Piledriver" Gen.
VirtualCenter 2.5 U2 and later updates Yes No No No No No
vCenter Server 4.0 Yes Yes Yes No No No
vCenter Server 4.0 U1 and later updates Yes Yes Yes No No No
vCenter Server 4.1 Yes Yes Yes Yes No No
vCenter Server 5.0 Yes Yes Yes Yes Yes No
vCenter Server 5.1 Yes Yes Yes Yes Yes Yes

Table 2.2: Intel EVC Baselines supported in vCenter Server releases

EVC Cluster Baseline
vCenter Server Release Intel® "Merom" Generation Intel® "Penryn" Generation Intel® "Nehalem" Generation Intel® "Westmere" Generation Intel® "Sandy Bridge" Generation Intel® "Ivy Bridge" Generation
VirtualCenter 2.5 U2 and later updates Yes No No No No No
vCenter Server 4.0 Yes Yes Yes No No No
vCenter Server 4.0 U1 and later updates Yes Yes Yes Yes No No
vCenter Server 4.1 Yes Yes Yes Yes No No
vCenter Server 5.0 Yes Yes Yes Yes Yes No
vCenter Server 5.1 Yes Yes Yes Yes Yes Yes

Notes:
  • For more information on supported servers and processor models, see the VMware Compatibility Guide for your ESX version.
  • Verify that the BIOS settings for host processors enable Hardware Virtualization (if available) and Execute Protection. Default BIOS settings might not always enable these features. Hardware Virtualization is Intel VT on Intel processors and AMD-V on (supported) AMD processors. Execute Protection is Intel eXecute Disable (XD) on Intel processors and AMD No eXecute (NX) on AMD processors. For machines with AMD processors, under Processor Options, set No-Execute Page-Protection to Enabled. Until these CPU features are enabled, ESX hosts with EVC supported CPU types listed below will be unsupported.

    Note: XD is also listed as Execute Memory Protection under the processor option within the server BIOS.

  • In EVC clusters where the ESX host CPU model is Intel 3500 or 5500 series (Nehalem), ESX 3.5 Update 4 or later and VirtualCenter Server 2.5 Update 4 or later must be installed. For additional information, see vMotion fails with an RDTSCP error in EVC clusters where the ESX host CPU Model is Intel 3500 series or 5500 series (Nehalem) (1011443). In EVC clusters where the ESX Host CPU model is Intel 3400 series, ESX 3.5 Update 5 or later and VirtualCenter Server 2.5 Update 5 or later must be installed. In EVC clusters where the ESX Host CPU model is Intel 7500 series, ESX 4.0 Update 1 or later and VirtualCenter Server 4.0 Update 1 or later must be installed.
  • For Intel® "Westmere" EVC Mode, some server OEMs might require you to enable the AES instructions in the BIOS.
  • E7 Series Processors require ESXi/ESX 4.1 Update 1 later. For more information, see Only one way migrations appear to function in an EVC cluster (2001373).
  • Hosts with Intel Penryn-E processors that are running virtual machines at the ESXi 5.0 compatibility level (hardware version 8) or higher cannot be added to Penryn EVC clusters. The ESXi 5.0 virtual machine compatibility level and higher compatibility levels expose the XSAVE feature to virtual machines running on Penryn-E hosts. The XSAVE feature is masked out in the Penryn EVC mode, causing a virtual machine feature incompatibility with these virtual machines.

References:

Third-party references:
Note: The preceding links were correct as of July 21, 2013. If you find a link is broken, provide feedback and a VMware employee will update the link.

Additional Information

For translated versions of this article, see:

Update History

01/10/2012 - Added ESXi 5.0 to Products 10/05/2012 - Fixed link to VMware Compatibility Guide.

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