Quickly jump to the changes.
In the figure above is GNOME Disks 3.10. We could select more than one disks and create a RAID Array.
In the figure above is GNOME Disks 3.11.x. We cannot create RAIDs anymore, while CSDs have been added.
There were two patches that arrived at the same time. The first was adding CSDs but was removing the ability to select multiple devices, hence the ability to create RAID arrays. The second was completely removing the support of creating MD-RAID.
If you already visited the patches, you would notice that aren’t linked to a bug tracker. I had the same question why this happened, and I asked David Zeuthen which is the main maintainer of GNOME Disks.
Removal of MD-RAID support had actually been planned for a while - I just haven’t had any time to work on the code-base until now :-) …
The feature was removed for the following reasons
- To make the user interface simpler; and
- To simplify the code-base; and
- MD-RAID never really worked well on Linux; the kernel parts are mostly fine but the user-space - especially the udev rules - would always get confused, especially on the error paths (e.g. drive failing); and
- There are now better things to use than MD-RAID, for example btrfs and ZFS. Whether we’ll add support for them in Disks is an open question. Probably not soon, there are more important things to work on right now (for example, pre-canned templates for formatting disks).
To be honest creating RAID arrays within GNOME Disks was just a nice to have feature, but with not casual use. Since it wasn’t working as expected, the drop makes sense. People that are interested in RAIDing they will probably use CLI anyway.
A nice source to get started with Btrfs