Continuing on from this https://sigtar.com/2010/02/04/vsphere-and-multipathing-iscsi/
you may want to implement jumbo frames to your iSCSI backend…
Enable jumbo frames on your iSCSI target and switches then complete the following on the ESXi hosts (iSCSI initiators)…
This to list your current switch details and port group names…
esxcfg-vswitch -l
The following to allow jumbo frames onto your vswtich (insert your vSwich in following)
esxcfg-vswtich -m 9000 vSwitch0
Then create your kernel port groups that you want to use for iscsi, my commands looked like this… (repeat for each iscsi kernel port you have) — note : DO NOT ADD ANY VMKERNEL(s) from the GUI, instead use the steps below
esxcfg-vswitch -A iSCSI vSwitch0
If you are using a tagged vlan you will also need to add the vlan tag to the above port group
esxcfg-vswitch -v 192 -p iSCSI vSwitch0
esxcfg-vmknic -a iSCSI -i 10.0.0.101 -n 255.255.0.0 -m 9000
To confirm you have set the MTU (frame size) correctely, run the following….
esxcfg-vmknic -l
you should see your iSCSI kernel ports with a MTU of 9000 all going well. Confirm connectivity using
vmkping –s 9000 10.0.0.10