Enable blk_mq on Redhat (OEL/Centos) 7 and 8
The IO scheduler blk_mq was designed to increase disk performance – better IOps and lower latency – on flash disk systems, with emphasis on NVME devices. A nice by-product, is that it increases performance on the “older” SCSI/SAS/SATA layer as well, when the disks in the back are SSD, and even when they are rotational…