Btrfs on top of a mdadm raid10, or btrfs raid10 on bare devices?

Question

I have a RAID10 managed by the mdadm and I have EXT4 filesystem on top of it. However, I like BTRFS and would like to convert the EXT4 filesystem to BTRFS, but I was thinking about performance and maintainability. For an example with BTRFS, I can't easily see the status when I remove/add another disk to the array like I can with mdadm (or perhaps I just do not know how - I searched through the BTRFS docs and could not find this).

So, from your experience, what is better choice:

1. To simply just convert the EXT4 filesystem and let mdadm manage the RAID10?

2. To get rid of mdadm, and let BTRFS do everything?

Answer 1

BTRFS is still experimental and you can end up with "interesting" features if something should crash. If you really have/want to run btrfs it would be for the time being a lot safer to run it on top of a software raid than to just run it directly. When btrfs matures and goes into production this might not be true anymore.