I would like to know the correct way to set up a software RAID array on an existing server. I have two brand new 3TB disks to use for the array.
Specifically, I want to set up a 3TB RAID 1 array, formatted to ext4, not using LVM. But a more general answer might help others with instructions from start to finish.
I have tried a number of guides:
- How to implement RAID 1? – only covers part of the process
- Setup of two additional SSD drives in RAID 1 – ends up with an array of 2TB rather than 3TB
- Add two new HDD in Raid 1 – only uses 1TB drives
I also found these resources:
- http://richard.blog.kraya.co.uk/tag/mdadm/ – for CentOS and does not cover updating
mdadm.confand other steps
- http://www.technotes.se/?p=1732 – comprehensive but complicated and not specifically written for Ubuntu
The initial partitioning of the drives appears to be key; the last link above mentions this in detail, but the previous link seems to achieve the same result and is simpler.