coffeeroasted

It should be active immediately. You have to make sure the share is loaded in macOS. It can't just be the server loaded, the individual folder has to be mapped. Actually, now that I'm testing a couple things to answer your questions, I realize that's all that needs to be done. The .cfg file doesn't need to be modified. What has to be done is the folder HAS to be mounted, not just the server. I tested this by creating a new time machine share, mounted it, and was able to see it in Time Machine. I didn't have to change the .cfg file at all.

That's strange. Mine have survived reboots and I didn't change anything from what I posted. I was under the impression that anything listed under /boot should survive reboots unless something changes it once it loads into RAM. Do you have any scripts running that may change your share .cfg files after boot? The only other thing that I could see affect it is if you make changes in the share GUI, as most changes made to the file are overwritten if an update is done in the GUI.

I was just referring to the issues people were mentioning re: Catalina. I don't know if it's specific to it or if the issue is in an unRaid update. I thought people were having able to get it to work on earlier OSs, but looking back in this thread, I don't think that's the case. I think it may just be an issue with unRaid's setup. All I know is that changing 'shareFruit' to yes fixes my issue, at least with backup. I haven't tried restoring at all.

This is the link I used to debug my share: Using Linux or Windows as a Time Machine network server. The things he points out that are required to enable Time Machine support were: The fruit module, which provides Apple’s proprietary extensions to SMB, The catia module, which maps the encoding of filenames that macOS expects to a form most native Linux filesystems can support, The streams_xattr module, which maps macOS’s extended attributes to a separate AppleDouble file, Optionally, the spotlight module, which builds a Spotlight search index on the server to speed up discovery of files in the backup, and Avahi, a multicast (aka Bonjour) daemon for Linux, used here to allow Macs on the network to discover the Time Machine share. I assume unRaid enables Avahi when macOS interoperability is enabled and I don't see anything in the config files supporting catia, streams_xattr, or spotlight, but it seems to work great between Avahi and the fruit module.

Hey, y'all. The issue with creating a Time Machine share with Catalina is due to a misconfigured setting in the share's .cfg file. For an SMB .cfg, Apple expects a setting to be passed called 'shareFruit'. For whatever reason, even when following @SpaceInvaderOne's video setup, the .cfg file passes a 'no' for that setting. Once you change the setting to yes, you'll be able to see it in Time Machine. The file is located at /boot/config/shares/***.cfg (*** being the name of your Time Machine share). I've reported the issue last week. It may be helpful for some people to comment on the bug report stating whether the change worked: https://forums.unraid.net/bug-reports/stable-releases/683-time-machine-share-r930/