I've been breaking my head over an issue I'm having with a 4-node MetroCluster FC (so 2 FAS8200 nodes per site) running in a production environment.
So I have two LIFs on the same controller, hosted on the same LACP group (tested with both one and two member ports). Accessing volumes through the first LIF, I saw latencies of up to 23ms. Accessing these same volumes on the second LIF, I saw latencies of up to 1ms. I'm measuring against volumes hosted on the same controller, as well as on the other controller, which gives me the same results.
I've done the usual things:
Checked CPU/disk utilization (sysstat -x on all controllers): less than 25% CPU usage in a few minutes, less than 70% disk usage.
Checked port usage through AIQUM: one physical port was using 9% of 10Gbps
There is no duplicate IP in the subnet
Any help/suggestions are greatly appreciated! If you need any output of commands or logs, I'll provide them. As I have quite some output already, I didn't add it to the post as it would be a long post.