The disk-collector could produce an empty fsSize array when
/host/proc/1/mounts is unreadable, causing the admin UI to fall back
to systeminformation's fsSize which includes tmpfs mounts. This led to
the storage display showing ~1.5 GB (tmpfs /run) instead of the actual
storage capacity.
Two changes:
- disk-collector: fall back to df on /storage when host mount table
yields no real filesystems, since /storage is always bind-mounted
from the host and reflects the actual backing device.
- easy-setup UI: when falling back to systeminformation fsSize, filter
for /dev/ block devices and prefer the largest one instead of blindly
taking the first entry.
Fixes#373
