s8kur

Membership in the libvirt group is root-equivalent, not a permissions fix. Through qemu:///system it lets you attach arbitrary host block devices to a VM, so anyone in that group can mount and read the host's own disk. If you want to manage VMs without root or that group, use qemu:///session instead: unprivileged, images live under ~/.local/share/libvirt, no sudo. Tradeoff is you lose bridged networking without a setuid helper.

Consensus is one of those areas where the interesting engineering and the number of people who actually need it are inversely correlated. Most "we need distributed coordination" turns out to be "we need one writer and a lock," which a single Postgres hands you for free: advisory locks, SELECT ... FOR UPDATE, SKIP LOCKED for work distribution. Linearizability without running Raft..

The real threshold is multi-region writes on a hard latency budget, and even then a single-region primary plus accepting cross-region read latency beats eating a consensus round-trip on every write for a lot of teams. Curious what workload pushed you past single-primary - usually a better story than the impl itself.