Slow NFS on VMware vSphere

I have Rockstor installed as a VM on SSD. I am running vSphere 6.0 and running on a 10 gbe NIC.

  1. How do I confirm Rockstor (the OS) believes it can run at 10 gbps?
  2. The NFS writes max out at about 500 mbps. Is there any way to troubleshoot?
  1. You can use iperf to verify the raw speed of your network link

2)The quickest way would be to use something like to see roughly how fast the array is able to write.

dd if=/dev/zero of=/mnt2/{pool name}/testfile bs=100M count=10 conv=fdatasync

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Well,I’m not sure which client is consuming the NFS endpoint. If you are using the NFS endpoint by vSphere itself (all-in-one setup?) than you have to keep in mind that ESXI is sending sync writes to the NFS share by default. Making it more secure, but slower.

Also see:

[root@rockstor ~]# dd if=/dev/zero of=/mnt2/share/testfile bs=100M count=10 conv=fdatasync
10+0 records in
10+0 records out
1048576000 bytes (1.0 GB) copied, 3.13213 s, 335 MB/s

Looks like 2.6 gbps

Okay so the array is fairly quick so that’s good. I would look into making sure that NFS is in async mode (what @Tim mentioned)

I would also run iperf and see what that says the link is. There is a pretty good right up on it in this thread