If you don't know alphaos started as archpup.
yeah alphaos now uses vdev instead of udev and its in beta.
are they connected via USB?
there have been alot of problems with usb thingies.
Could you post more info plz.
tree /dev > /tmp/dev.txt
and post dev.txt
in the meantime you could try to boot withhttps://www.dropbox.com/s/ch7gj5v75fbo4 ... bd.sb?dl=0
but thats a workaround