5 Tips To Speed Up Linux Software Raid Rebuilding And Re-syncing

Originally published at: https://www.cyberciti.biz/tips/linux-raid-increase-resync-rebuild-speed.html

It is no secret that I am a pretty big fan of excellent Linux Software RAID. Creating, assembling and rebuilding small array is fine. But, things started to get nasty when you try to rebuild or re-sync large size array. You may get frustrated when you see it is going to take 22 hours to rebuild the array. You can always increase the speed of Linux Software RAID 0/1/5/6 reconstruction using the following five tips.

Hey!
At starto sorry for bad english.
I want to expand from RAID 1 (2x8TB) on my NAS (DS918+) to RAID 5 (4x8TB).
Can I use all 5 tips to migrate form RAID1 to RAID5 without loosing my data?
Or I should use only some steps from post?

@Cykor

No, you can’t migrate RAID1 to RAID 5 without data loss.

From synology site:
“Storage pools can be changed from one RAID type to another without losing existing data”
No data loss from Raid 1 (drve 1 and 2)
“Please note existing data on the added drive shall be deleted.”
Data loss from added drives (drive 3 and 4)

https://originwww.synology.com/en-global/knowledgebase/DSM/help/DSM/StorageManager/storage_pool_change_raid_type

Synology must be using something proprietary via their firmware. It is not possible on your typical Linux server powered by Linux distro such as CentOS/RHEL/Fedora/Ubuntu and so on