Poor iSCSI Performance

[mullinsj08]

Hi all,

I need some advice on improving the performance of my FreeNAS server. It is primarily used to provide iSCSI storage to my 2-node ESXi cluster but currently the performance is absolutely horrid. Below is the specs of my FreeNAS:

- Intel Xeon E5-1620v3
- SuperMicro X10SRi-F
- 128GB DDR4 ECC PC4-19200
- 128GB SSD boot drive
- 12x Western Digital Gold 2TB SATA 6Gb/s 7200RPM WD2005FBYZ in RAIDZ2 (6 vdevs of 2 drives each).
- Intel i350 for management
- Intel X550-T2 for iSCSI (Each NIC on a different subnet and VLAN for multipathing).
- FreeNAS 11.1 Update 6

These are the specs of the 2 ESXi hosts which are connected:

- Dell PowerEdge R730
- 1x Intel Xeon E5-2620v4
- 128GB DDR4 ECC PC4-19200
- Intel i350 for management/VM traffic
- Intel X550-T2 for iSCSI (Each NIC on a different subnet and VLAN for multipathing).
- VMware ESXi 6.7 Update 1 (Dell Customised)

The switch I'm using is a Netgear XS708T, jumbo frames are enabled on the switch, FreeNAS and both ESXi hosts. The path selection policy in ESXi is set to round-robin after every 1 IOP.

There are about 30 virtual machines running across the 2 hosts.

Reading off one of the servers onto a Intel Skylake laptop with an SSD connected via ethernet gets speeds between 30 and 70mbps and writing to one of the servers starts at 113mbps, after a few seconds falls to 0 and then bounces between 0 and 20mbps.

I'd really appreciate some advice, if there is something I haven't covered please let me know!

 

[dlavigne]

Did you find the root cause for this?

 

[mullinsj08]

Not yet, still trying to figure this one out.