User shares are simply the combined top level folders on all array and pools. They are mounted at /mnt/user. Normally, each user share appears separately on the network. A user share named media is /mnt/user/media. When you work with a specific user share, Unraid applies the settings for that user share to anything you do with the share.

 

The rootshare is /mnt/user itself, which contains all of the user shares. If you are working with rootshare, Unraid can't apply any specific user share settings since rootshare is all shares.

Thank you all for your responses and taking the time to answer. I understand better the structure of rootshares. But like I said, the weird part is that I was able to get cache drives working with the manual rootshares method detailed in SpaceInvaderOne's video here:

The Unassigned Devices plugin method never used the cache but the SpaceInvaderOne's did.

 

Still don't know why.

 

I just did a complete rebuild of Unraid and will experiment with these two methods to see why they differ.

 

Also, apologies for the long pause.

Well, wouldn't you know. I just started syncing some files via my newly minted smb rootshare and it is clearly using the cache drive. This is via the Unassigned Devices plugin method. Any clue why?

 

Either way I'm pretty pleased.