I just went through a reinstall of Tumbleweed and when reconfiguring my secondary ssds, I got this message after fixing my fstab to mount my previously configured btrfs disks:
“does not contain SELinux labels. You just mounted a file system that supports labels which does not contain labels, onto an SELinux box. It is likely that confined applications will generate AVC messages and not be allowed access to this file system. For more details see restorecon(8) and mount(8).”
I know openSUSE just changed from AppArmor to SELinux, but is this going to affect my previous file systems?
It is not going to affect your previous file systems, but the state of your previous file systems may affect the ability to access them from your new installation. I find the quoted message pretty clear.
If you do not want to permanently set SELinux labels, you can use mount options like context= or defcontext=. See man 8 mount.
You can also switch back to AppArmor if you find it more familiar.
I copied over the data on those disks onto another HDD, formatted both of them into btrfs and added labels to both and it complains they have no labels.
I don’t mind adapting to new systems and learning.
Highly simplified - SELinux works with security labels attached to the processes and files. Process label is usually called domain and file label - context. SELinux policy is a collection of rules that define what processes (domains) are allowed to do with files (contexts). Anything not explicitly defined by the policy is not allowed.
The message simply tells you that if the current policy does not include rules granting your processes (domains) access to the unlabeled files these processes will not be able to access files on this filesystem.