But I haven’t found out what happens and how does it work when I insert the mSATA drive into my Omnia and turn on Plugin Storage and then add a NAS (Samba) or NextCloud plugin for example?
What data is then included in the Schnapps snapshot?
It’s filesystem-level snapshotting. External drives have a separate FS, so I believe they won’t be included. (by default, at least; btrfs can handle FSs that span multiple devices)
It won’t. From practical perspective I’d suggest to snapshot /srv separately anyway, though that depends on your particular use case. For example, when you roll back your system/config, you probably don’t want your newest photos to disappear.
Does the TOS write any of its system files to /srv?
I wonder if there is a possible bad scenario that Schanpps will take a snapshot without /srv (because it was moved from eMMC to mSATA) and then there will be some conflict after restoring any snapshot (because in /srv on mSATA there will be files unexpected by TOS from another shutter).
If I am thinking correctly