collectDiskIO hand-rolled a partial exclusion list (loop, ram, dm-) while
the two sibling paths, agent SMART collection and the server-side resource
registry, both use fsfilters.IsVirtualBlockDevice. ZFS zvols were therefore
collected as if they were physical disks: a Proxmox host with ZFS-backed
guest storage exposes one zd<N> device per zvol, so a few hundred guests
produced a few hundred phantom disks in every agent report, driving
sustained metrics and resource_changes growth.
Route the filter through the canonical helper so zd, zram, nbd, rbd, drbd,
md, pmem, vd and xvd are all excluded. md and dm- aggregates additionally
restated the I/O of their own physical members, so counting them alongside
those members double counted host disk I/O.
Refs #1671
rcourtman
99ad8c2c4b