What should be the MTU size for maximum NAS access through iSCSI?

Question

Computer networks

There is a Hyper-V 2012r2 cluster connected directly to ReadyNAS netgear via 10Gb Ethernet via iSCSI.
Accordingly, virtualok hard disks are stored on NAS.
What should be the MTU in this direct connection so that the speed of reading / writing to the virtual disk is maximum?

Answer 1

Usually this is 9000 bytes, but it can be more - it depends on the hardware developers. This feature is called jumbo frame, it must be supported and enabled on all equipment from the sender to the recipient, otherwise it will not work. Disabled everywhere by default.
See network adapter settings on servers, storage and network switches between them.

Answer 2

Try to put 9k, but I think the speed of the disks will be the bottleneck.