Best way to grow Linux software RAID 1 to RAID 10
- by Hans Malherbe
mdadm does not seem to support growing an array from level 1 to level 10.
I have two disks in RAID 1. I want to add two new disks and convert the array to a four disk RAID 10 array.
My current strategy:
Make good backup.
Create a degraded 4 disk RAID 10 array with two missing disks.
rsync the RAID 1 array with the RAID 10 array.
fail and remove one disk from the RAID 1 array.
Add the available disk to the RAID 10 array and wait for resynch to complete.
Destroy the RAID 1 array and add the last disk to the RAID 10 array.
The problem is the lack of redundancy at step 5.
Is there a better way?