After connecting to Linux, use /proc for CPU, memory and network counters, and df for filesystem space. Confirm the host and sample time first. Interval CPU utilization and network rates need two samples.
Confirm the server you are inspecting
These commands read information from an authorized Linux host. Replace the example username and address and verify the first-use fingerprint. Minimal systems may lack some common utilities.
ssh [email protected]
hostname
date -u
uptimeCPU: cumulative time is not current utilization
The cpu line in /proc/stat contains cumulative counters, not an instantaneous percentage. If a tool shows no value on its first sample, wait for another. Missing data is not 0% utilization.
head -n 1 /proc/stat
sleep 2
head -n 1 /proc/statMemory: look beyond free memory
MemAvailable estimates memory available to new applications without swapping. Caches affect how MemFree should be interpreted. Check definitions before comparing tools; low free memory alone does not establish exhaustion.
grep -E '^(MemTotal|MemFree|MemAvailable|Cached|SwapTotal|SwapFree):' /proc/meminfoDisk: the root filesystem is not every mount
df -Pk / checks the root filesystem; df -Pk includes other mounted filesystems. Identify the mount that contains application data before investigating capacity. Root usage does not describe a separate data volume.
df -Pk /
df -PkNetwork: byte counters are not rates
Read the same interface twice and divide the receive or transmit byte difference by the actual elapsed seconds. After an interface reset or counter decrease, discard the old baseline.
Example: a receive counter increases by 2,097,152 bytes over 2 seconds, giving about 1 MiB/s. This illustrates arithmetic, not a product benchmark. Adding bridge and physical-interface traffic may count the same traffic twice.
cat /proc/net/dev
sleep 2
cat /proc/net/devReduce repeated switching during inspection
Commands suit one-off verification. For repeated checks, shellivo can collect readings and provide a terminal for the corresponding host. When tool and command values differ, align sample times, interfaces and mount points before suspecting a collection problem.
Questions
Does a missing value mean zero resource use?
No. Check the connection, permissions, commands and sample interval to establish whether a valid new sample exists.
Do these commands replace continuous alerting?
No. They inspect status when run; continuous alerting also needs scheduled collection, storage, evaluation and notifications.
shellivo
Check supported platforms, available downloads and installation notes.