Add RAID to gravity

[rkevin-arch]

There is a potential for loss of uncommitted items to the control-repo and metalc-configurations repositories that make it potentially nice to have raid.

[sandertyu]

Metalc-configurations is not located on gravity and the control-repo should be edited locally then changes pushed after (specified in documentation). Theoretically we could have data loss if someone did edit the control-repo on gravity then the drive failed before pushing, but this should be unlikely. RAID is still a nice to have, but may not be worth the effort. I'll at least change to low priority unless someone else wants to close.

[moorepants]

Add to control repo's documentation a clear warning that control repo should not be edited on galaxy (if not already there). Make sure everyone is aware (via a PR) and then close this issue.

[sandertyu]

There is a section in the README (added after the previous meeting but before today) of the control-repo which suggests to edit the files locally and the push/pull to the repo on gravity. On occasion it is useful to edit the files directly on gravity such as when we need to debug small changes to helm values (config.yaml) and then run upgrade scripts to test the changes.