Concern: Supersize io operations (IO block size more than 4KiB) is split in to number of 4KiB blocks

Supersize io operations (IO block size more than 4KiB) is split in to number of 4KiB blocks

OS: CentOS 7.3

kernel Version: 3.10.0-514.el7.x86_64

Any IO (write) block size more than 4KiB is split in to number of 4KiB blocks on Centos 7.3 ( where I don't see similar issue on 7.2). I have a setup that involves TWO CentOS 7.3 servers. I tried to run 4MB IO on FC LUN(s) on these servers discovered through Emulex LPe 16000 HBAs.

Changed ‘options lpfc lpfc_sg_seg_cn =>1024’ and ‘max_secors_kb =>4MB’ params towards attaining supersize IO ( 4MB block size) , however there are no improvements in getting more than 4K block size IO. There was no impact from these changes.

Looking for a help to tune the system to attain supersize IO operation (4MB writes)

Regards,

Sk