The periodic check spawned one `pct status` per container and one
`qm status` per VM each cycle. Both are heavy Perl tools (~hundreds of ms
CPU per invocation), so on hosts with many guests the 5-minute run caused
a noticeable CPU spike.
- Derive LXC status from the single `pct list` call that is already made
for enumeration.
- Add one `qm list` call to collect all VM statuses at once.
- Store both in a per-cycle STATUS_CACHE and read from it instead of
calling `pct status` / `qm status` per guest (with a fallback for direct
calls outside the cycle).
MickLesk
b1d73e646b