low migration rate between two iscsi storage systems on 1 esxi host

[AndrewAkim77]

Hello, sorry in advance for my poor English.
I have 1 esxi 6.7 host, it is connected to 2 storage systems via 2 x710 iscsi network cards, one card to 1 system. There is also a local storage on the esxi host itself. If I move an in vCenter vm-machine from network storage to local storage, or from local storage to network storage, I have a speed of 1 GB per second, this applies to both network storage, but if I migrate from one network storage to another, then the speed of movement does not rise above 250-300 MB per second, and I I can't understand what is the reason for such a low speed.
Each of the x710 network cards has 2 uplinks that are connected to separate standard switches. The two storage systems are located in different subnets, and accordingly each card looks into its own subnet. For management, a separate 1 Gigabit network adapter is used.

[maksym007]

I feel the need - the need for speed 🙂 

To be honest I do not know what you are expecting from adapters with 1GB/s.

Even if you create a LAG it will not improve drastically.  Ask a client to buy new FC Cards with SFP modules 10 GB/s or 25 GB/s and you will feel speed 

[AndrewAkim77]

I probably put it badly, the host has 2 Intel X710 adapters-based on 2 10 Gbit uplinks each. 2 uplinks for each storage system, in a working Round robin 20 gbps. When migrating from any iscsi storage to local storage, I get speeds at the level of 10000-12000 mbps, but when I migrate between iscsi systems, my speed does not exceed 2000mbit, and I cannot understand why.

iscsi storage fujitsu eternus 200s5 with 12sas ssd in raid6 and iscsi dell 3820 with 24 sas 10k hdd in raid 10.

[Yoshimotto]

Hi,

Have you check the MTU settings on the switch, vmkx, vswitchs, portgroup ... ?

The best practice for the MTU on iSCSI is 9000 (JAMBO FRAME).

Check the setting on the fastest to be shure.

[AndrewAkim77]

Unfortunately, there is no way to enable jumbo frames, we use a stack of 6 cisco 9300 and enabling leads to a disruption of routing between this stack and the further network structure.

I thought that this was due to the slow operation of the soft driver from vmware esxi, since VAAI does not work in this bundle, and I thought that someone would tell me about the features of the esxi Store vMotion implementation.