vSphere 6 FT Performance Issues

[netanelbs]

Dear All,

I got VMware vSphere 6 clean environment (with latest updates) on top of IBM x3550 M5 servers.

I'm working with 10Gbps Ethernet NICs for VMKerne port group with FT Logging services on, and when I'm enabling FT on single Windows Server 2012 R2 VM with one vCPU (not even 4 vCPUs), the performance are sluggish. For example, PING latency is high (just like in this thread - https://communities.vmware.com/thread/515877) and also, when I'm trying to copy files such as 100MB is taking too long or doing other stuff such as opening Notepad.exe.

I'm working on top of VMFS datastore, and the VM working with Thick lazy disks.

When of course, I'm disable the FT everything running properly.

Any ideas? Suggestions?

Please assist.

Thanks,

Netanel.

[vbrowncoat]

FT is likely operating normally. FT (especially SMP FT) because of how it functions in having to keep two VMs running on 2 different hosts in sync adds latency. When a packet is received by the primary VM that has to be sent to the secondary, received and acknowledged before the primary can acknowledge receipt of the packet.

See this whitepaper for details on performance testing with FT: Fault Tolerance Performance in vSphere 6 - VMware VROOM! Blog - VMware Blogs

[pterlisten]

Hi Netanel.

unfortunately it's true: FT-SMP is not a good choice, if you want to protect latency-sensitive applications. Therefore there is nothing you can do, except disabling FT-SMP or switch to legacy FT (but then only with 1 vCPU).

[netanelbs]

Thanks Patrick!

I'll try on Monday configuring Legacy FT according to this document: vSphere 6.0 Documentation Center and let you know what's happening.