Compatibility Intel Xeon 4core - 6 core

[P2Ver]

Hi Guru's

I have a question about the purchase of a new server for my vSphere cluster environment:

Currently I have a 2 node cluster with two identical HP DL380G6 servers. (491315-421)

They both have

2x Intel® Xeon® X5560 (4core, 2.88 GHz)

Now I want to add a new server to my cluster, it's also an HP DL380, but its a G7. (583966-421)

It has newer CPU's;

2x Intel® Xeon® X5650 (6core, 2.66 GHz)

Since theres a difference between the cores and speeds, I was wondering whether this will work out right.

Is FT still working? Is my environment still compatible?

I hope to hear from you guys soon!

Thanks in advance!!

[Snipe]

Hi P2Ver,

take a look to this pdf (http://www.vmware.com/files/pdf/fault_tolerance_recommendations_considerations_on_vmw_vsphere4.pdf). Specifically page 10 when it says "The ESX hosts in your cluster should be as uniform to each other as possible – as described in the Cluster and host requirements section. For better performance, the hosts running the Primary and Secondary VMs should operate at roughly the same processor frequencies in order to ensure the highest level of fault tolerance. Processor speed differences greater than 400 MHz in frequency may become problematic for CPU-bound workloads."

[P2Ver]

Thanks for your quick reply!

But, than again, if one of your cluster nodes fails, and you'll have to replace it, it'll always be a newer type of server.

Than you'll have a major incompatibility with other 'older' hosts.

This worries me; I really need the new server, but now it seems that it wont fit in my cluster?

What to do?

[mittim12]

You can check out this link for FT processors, http://kb.vmware.com/kb/1008027.

As far as VMotion you could maybe use EVC.   Check out this link for more information, http://kb.vmware.com/kb/1003212.

[chriswahl]

P2Ver wrote:

Since theres a difference between the cores and speeds, I was wondering whether this will work out right.

Is FT still working? Is my environment still compatible?

Enabling FT might not work, but then again it's a very niche feature that few people use in production. My thought is that it won't work between the new 5650 and the older 5560.

As for the rest, enable EVC on your cluster and all should be well. I'm running nearly an identical setup (380G6 mixed with 380G7) without issues.

[P2Ver]

Hi Chris,

To be sure, I've contacted Vmware tech support, and just like you they've mentioned to use EVC for vmotion.

They also told me FT should work in this configuration!

I will quote tech support's answer:

"I can confirm that there will be no problem with FT between the 55xx and 56xx series CPUs, these both inhabit the same category (Intel Xeon based on Core i7 Microarchitecture) and that is all that is required, they need not be identical.

What may pose a problem is vMotion as the 56xx CPUs will have newer features that will not be supported by the 55xx series CPUs, this would mean that VMs running on the host with the 56xx CPU could not be hot vMotioned to a host running the 55xx CPUs, powering off the VM would allow migration as the VM would release the newer features.

To avoid the issue of vMotion compatibility we would recommend enabling EVC (Enhanced VMotion Compatibility). This will mask the newer features on the 56xx CPU and allow VMs to vMotion freely between all hosts in the cluster. The baseline to use for this purpose would be "Intel® Xeon® Core™ i7 EVC Mode", full details of EVC can be fond in the KB linked below:

http://kb.vmware.com/kb/1003212 - Enhanced VMotion Compatibility (EVC) processor support"

Thanks everybody for assisting me!

I hope I can be at help someday:)

[P2Ver]

IMPORTANT INFORMATION!!! : FT bug in ESX 4.1.0, 260247 

I have to make this important comment on this topic, since Vmware support told me that my vSphere cluster with 2x Intel Nehalem X5560 CPU's and 1x Intel Westmere X5650 would be FT compatible.

I tried to set up an FT pair, but on my newest host with the XX5650 CPU, it gave the following error:

Host CPU is incompatible with the virtual machine’s requirements Mismatch detected for these features:

CPU model does not match

After contacting Vmware support, they told me they came across an internal bug report that notes an issue with FT and 55xx and 56xx CPU series that appeared in ESX 4.1. and is resolved in ESX(i) 4.1 Update 2 502767.

I was running ESX 4.1.0 260247. The solution they mentioned was:

The first step would be to upgrade your vCenter Server and Update Manager You can download vCenter 4.1 Update 2 from

http://downloads.vmware.com/d/details/vc41u2/dHdlYnRoaGRidGVwKg==

The best practice when upgrading your vCenter Server would be the following:

1. Stop the vCenter Server Services and Update Manager Services

2. Take a backup of the vCenter Server Database and Update Manager Database.

3. Run the installation media from the link above *Please ensure to select "Use existing Database"*

4. Run the Update Manager installation from the media from the link above *Please ensure to select "Use existing Database"*

5. Once all installations complete, restart the vCenter Services and Update Manager Services.

Next you can use Update Manager to upgrade the ESX 4.1 Hosts to Update 2 502767 For more on Update Manager please see

http://www.vmware.com/pdf/vsp_vum_41_admin_guide.pdf

This solution worked for me, and so my vSphere cluster with the Nehalem and Westmere CPU's is Fault Tolerance compliant again!

Thank you very much Vmware Support!! \o/