Have you mounted the drives yet?
Can you create directories and files on these drives? If so I have no idea what the problem is.
I ended up rolling back everything, including OMV-Extras, rebooting and then going again. Worked this time. Probably some n00b mistake on my part. Thank you for responding to my cry for help 
#619: I originally tried having them as wiped and blank, and have since my post tried having them individually formatted (XFS) under Filesystems. Alas, didn't change the behavior of SnapRaid dropdown menu.
I can add that the setup is an Intel DQ77KB motherboard with 16GB RAM, 3470T CPU. OMV is installed to a Samsung 256GB miniPCIe SSD, the four disks are all 1TB Seagate 2.5" - ST1000LM035-1RK1. All the 1TB disks are set up to not power down. I want to do spindown, but I figured they might have trouble spinning up fast enough for the listing in the dialogue box to catch on. But that didn't change anything.
Hi,
I am totally new to OMV and is trying to test out using it with SnapRaid. But I am having some weird trouble selecting disks.
I have 4x 1TB disks that I want to set up as 3 data drives with content file and 1 disk as parity,
Have installed the OMV-Extras and the SnapRaid plugin. The disks are empty.
When I open SnapRaid->Drives and choose to Add drives, I get a pop-up. When I select the dropdown list I get a millisecond of an updating spinning arrow and then the list is empty.
But the disks are there and they do show up if I for instance try to create a regular raid.
Really have no idea but have tried to remove SnapRaid, reboot, reinstall, reboot - but it stays the same.
Any help would be appreciated
I have attached my syslog.
