PSI Made Short Resource Spikes Easier to Interpret
Some periods looked acceptable in average CPU and RAM graphs while interactive services still felt slow.
PSI
Container I/O Pressure Shows Waiting, Not Just Bytes
A workload can perform modest disk throughput and still suffer because requests are waiting behind slow storage or competing I/O.
Memory Usage Is Not the Same as Memory Pressure
The host looked busy enough that a simple percentage could easily become the whole diagnosis, but Linux memory reclaim makes that misleading.