Adjusting initialization/resync speed

Linux by default has a speed of 200MB as the speed for volume assembly and synchronization. This was the community standard set based on spinning platter based hard drives. A consensus has not been reached regarding what the standard should be moved to with the advancements in technology.

This value can be modified to prevent the system from taking an undue amount of time initializing or rebuilding a RAID array. The series of commands below shows a system that is set at the default value, and how that may be modified.

To see what the current rate of speed the system is using:

# cat /sys/block/md0/md/sync_speed_max
200000(system)

To modify this to a higher value, such as 5GB for NVMe drives:

# echo 5000000 > /sys/block/md0/md/sync_speed_max

NOTE: Different values may be appropriate for different drive types. 5GB is reasonable for Data Center Intel NVMe SSD models.