I'll try again. Let's say sda,sdb,sdc,sdd,sde make up a snapraid pool. a,b,c are data and d&e are parity. Let's say I've created a merger-fs mount that combines a directory on sda and sdc. Now, can I put the mergerfs mount directory on sda or sdb or sdc without confusing snapraid? Or must I exclude that directory from snapraid?
I have physical data disks sda, sdb, sdc, sdd, and sde. OMV is on a small SSD sdf.
I set up SnapRaid using the plugin with data disks sda, sdb, sdc, and sdd; parity is on sde.
I setup mergerfs by hand in /etc/fstab (the plugin will not allow me to use directories as sources, it only allows entire drives to be used).
I have the megerfs mountpoints on sdc.
I do not exclude the mergerfs mountpoints from SnapRaid, and there have been no problems.
If there were going to be problems with this (I suspect you are thinking of a circular reference type situation), then I would have put the mergerfs mountpoints on the rootfs which is not seen by SnapRAID at all.
Thank you gderf. That answers my question. (I was thinking about the possibility of a circular reference) My configuration is very similar to yours. I would put the mergerfs mountpoints on the rootfs, but then OMV doesn't allow you to share them! At least not through the webui - one could always edit some conf files and make it happen I suppose.