We have built a SAN using Nexenta and 10Gbe for our VMWARE environment and with some tweaking and testing I am able to hit up to 1GBytes (not Gbps) per second to the SAN using iSCSI from a Win 7 Guest VM according to ATTO Disk Benchmark. But im running into slow performance issues connecting to the same SAN over the same network from inside a VM Guest using Windows 7 and the VMXNET3 adaptor.
Config:
ESX using 2x 10GBe NIC's via Vswitch over iSCSI to SAN with 2x10Gbe NICs
Guest VM OS drive is on the data store that is on the SAN over ISCSI
Performance on C drive is 800-1000MB/s
Now when we map a network drive to the same SAN using CIFS over the same vswitch im hitting only approx 100MB/s although the network card in my VM guest shows its connected at 10Gbe
When I try to connect the VM Guest to the SAN via the Microsoft ISCSI initiator i get identical results so I'm pretty sure its not the SAN causing the bottle neck. Below is a benchmark of an attached ISCSI disk to the Vm guest.
Even when i copy files locally on the guests C drive i can easily copy a 4GB file in 10 seconds, but same file from c drive to network folder is 10x slower.
Message was edited by: saschad