I’ve been going back and forth with this issue for some time but honestly I have no idea if the vCenter telemetry is something to rely on. I’m experiencing rather high latency on the storage on my VMs, most of them idle, only vCenter and virtual firewall generate some IOPS, 5 are shut down, other 3 VMs are linux machines that idle for 99%, even though they can spike 100ms per IO. Today I have decided to migrate a VM storage to another server to find that higher disk utilization reduces the latency on the host, how that makes any sense? I’m using P420 in RAID 10 with 4x4TB 7k SAS HDDs.
Host latency:
GID VMNAME NVDISK CMDS/s READS/s WRITES/s MBREAD/s MBWRTN/s LAT/rd LAT/wr12953 dns - 1 0.00 0.00 0.00 0.00 0.00 0.000 0.00016904 fw - 2 5.84 0.00 5.84 0.00 0.02 0.000 18.40820481 vcsa - 13 16.58 0.00 16.58 0.00 0.08 0.000 37.582130847 - 2 0.00 0.00 0.00 0.00 0.00 0.000 0.000626694 deb - 2 12.06 0.00 12.06 0.00 0.46 0.000 6.586as you can see the is no much IOPS per VM, like vcsa VM latency I captured is floating between 20 and 100ms, while deb has similar IOPS but lower latency