Max MTU size 3616

[drugit]

We are moving some of our blades from FC to ISCSI, with centos 7.6.1810 3.10.0-957.12.2.el7.x86_64 all went smooth, but with CloudLinux release 7.6 3.10.0-962.3.2.lve1.5.25.8.el7.x86_64 some odd things: at boot: ip=192.168.1.2:::255.255.255.0::enp2s0f2:none:9000 : ifcfg-enp2s0f2 generated by dracut have MTU="9000" runtime: ifconfig enp2s0f2 mtu 9000 but result is: enp2s0f2: flags=4163 mtu 3616 Hardware for centos7 and CL blades are identical. bnx2x: QLogic 5771x/578xx 10/20-Gigabit Ethernet Driver bnx2x 1.712.30-0 (2014/02/10) Switch and network too. Any one have any ideas how to change MTU to 9000?

[avarlyga]

Hello, most of all the issue related to the different versions of the driver that exists in CentOS and CL kernels Please, try to find out details using "modinfo" for example:

[drugit]

Answer from developers:

> Our kernel does not support mtu values greater than 4000.

Strange decision in my oppinion, using iSCSI you need 2 frames to read/write 4k, or 3 frames for 8k. Hope they rise this limitation.

[skhristich]

Hello,
To help you with this question we need a little bit more information, please create a ticket here https://cloudlinux.zendesk.com/hc/en-us/requests/new
and technical experts will help you asap.
If you have any other questions, feel free to ask here.
Thank you for contacting us.

[drugit]

Hm, i got this answer from there:

> Our kernel does not support mtu values greater than 4000.

[skhristich]

Hello,
Right now theres no way to raise this limit above 4000. Weve made a task to the developers team (internal ID is CLKRN-471); well see if we can improve that in the future. Thanks!

[winstinalaw415]

> Hello,
> Right now theres no way to raise this limit above 4000. Weve made a task to the developers team (internal ID is CLKRN-471); well see if we can improve that in the future.
> Thanks!

ok sir got it . will keep it in mind.