Recently we've set up a two Windows Server 2012 Datacenter as Hyper-V nodes in a cluster.
The nodes have dual Intel E5-2620 CPU's at 2.00GHz for a totall of 24 logical processors.
Each node has 16 DIMMs of 8GB for a totall of 128GByte RAM. Low voltage DDR3 modules.
Both nodes have a dual port QLogic 3242 convergered ethernet adapters.
The ports are set up using NPAR to each have four virtual NICs, of which both last two are set to a max bandwidth of 9Gbit/s.
There are four teams created over the four vNICs. Management, Virtual Switch for Hyper-V, Live Migration, and iSCSI.
All are set up as Failsafe Teams, meaning only one port is used actively.
iSCSI teams are set up to use a Max Ethernet Frame Size of 9614, and pings to the Netapp SAN respond to a 8000 packet size ping.
The nodes are all very fast and responsive. It is the VM's that I find too slow in several ways.
On of the main things I've bee noticing with Hyper-V so far, and we still have a 2008 R2 cluster from which I am migrating to the new 2012 cluster, is the relative slow performance of the VM's. Sometimes they are slow to respond to a RDP connection, slow response with starting programs.
The most odd thing I have witnessed so far is Quick formatting a virtual hard drive inside a Windows Server 2012 Standard VM.
A 40GByte drive (GPT, NTFS with Default sector size) takes about 5 minutes. Never had that problem on 2008 R2.
Both clusters connect to the same SAN using the same NIC configuration.
It sounds to me like a I/O problem, but I can't figure out why.
For example: When I migrate VM's from the 2008 R2 cluster to the new 2012 cluster (manually, since the Failover Cluster wizard cannot handle VM's created in SCVMM 2008 R2), and then Convert-VHD them to another drive to a VHDX file, it's runs at 1 to 1.4Gbps
in both ways. Oddly enough the Move-Item back to the Original location does it in half the speed (which I assume is a bug in Move-Item).
This makes me believe the I/O is just fine for the host, so why is it so damn slow in the VM?
Although when I copy a file from the local hard drive of the host to a hard drive inside the VM, from within the VM, it shows a 1 to 1.6Gbps speed. Totally fine.
Is it just some weird bugs that exist in Hyper-V 2012, and will those be fixed in R2 or is it something else that I am missing?