RAID Volume Takes a Really Long Time to Rebuild/Synchronize in Intel® Virtual RAID on CPU (Intel® VROC) for Linux*

After a clean installation of a Linux* based operating system on a Intel® VROC RAID 1 volume (for example RHEL 8.3), the estimated synchronization time is over 700 minutes, which is not acceptable for NVMe* drives, taking into consideration that there is no information to syncronize besides the operating system data.

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, with X representing the number to be modified depending on the volume.

• To see what the current rate of speed the system is using (generally 200000 or 200MB):
  • # cat /sys/block/mdX/md/sync_speed_max
• To modify this to a higher value, such as 5GB for NVMe* drives:
  • # echo 5000000 > /sys/block/mdX/md/sync_speed_max

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