I currently have two identical drives set up in a RAID-0 configuration, but I'm looking to increase reliability by adding redundancy without rebuilding my setup from scratch. If I create a RAID-0 volume now, can I later add two more identical drives and turn it into a RAID-10 array on the fly? I'm specifically avoiding using ZFS. My alternative plan was to set up a degraded RAID-10 with the existing drives and then repair it once the new drives arrive, though I'm not too fond of that option. Ideally, I want to achieve this upgrade without having to rebuild the entire RAID structure and transfer data again in a couple of weeks. I've read that some experts mention this isn't feasible, but I doubt that.
3 Answers
If you want to be extra safe, consider making a new RAID-10 setup with the two new drives and leave every other drive out initially. Once you've moved everything over (using `cp` for speed), you can dismantle the old RAID and add the remaining drives to the new setup. Just make sure the partition sizes match up!
Great news! It turns out you can indeed grow a RAID-0 into a RAID-10 without too much hassle. Just run the command: `mdadm --grow --level=10 /dev/md0 --add /dev/sdc /dev/sdd`. This will change your RAID level to 10 and add the new drives seamlessly. I tried it myself and it worked without issues!
Why not test it in a virtual machine first? It could save you some headaches while figuring out the exact steps.
I definitely plan to, but I'm looking for a few pointers to get started.
That's pleasantly simple, glad I came across this!