System Info

System Info

Collect host diagnostics and resource metrics.

Before running commands, detect the OS and load the matching reference for platform-specific syntax:

• Linux — references/linux.md (procfs, sysfs, GNU coreutils)
• macOS — references/macos.md (sysctl, vmstat, diskutil, systemprofiler)
• Windows — references/windows.md (PowerShell: Get-CimInstance, Get-Counter, Get-Process)

OS detection:

uname -s 2>/dev/null || echo Windows

Workflow

1. Gather only the metrics the user requested — do not dump everything.
2. Prefer read-only, non-invasive commands. Never change system settings unless explicitly asked.
3. If a command is unavailable, check the OS reference for a fallback.
4. Return a short summary with key numbers (percentages, GB, top processes).
5. Flag values that indicate problems (see thresholds below).

Diagnostic categories

OS and kernel

Identify the operating system, distribution, kernel version, hostname, and architecture. Useful as a starting point for any troubleshooting session.

Key information to collect:

• OS name and version (e.g., Ubuntu 24.04, macOS 15.2, Windows 11 23H2)
• Kernel version
• System architecture (x86_64, arm64)
• Hostname

Uptime and load average

Determine how long the system has been running and its current load.

Interpreting load average (Unix):

• Three numbers represent 1-minute, 5-minute, and 15-minute averages
• Compare against CPU core count: load equal to core count means full utilization
• Load consistently above core count indicates CPU contention
• Rising trend (1min > 5min > 15min) means load is increasing

CPU

Inspect processor model, core count, current utilization, and per-core activity.

| Metric | Healthy | Warning | Critical | |--------|---------|---------|----------| | Overall utilization | 90% sustained | | Load avg / core count | 2.0 | | I/O wait | 30% |

Memory

Check total, used, free, available, cached, and buffered memory plus swap usage.

| Metric | Healthy | Warning | Critical | |--------|---------|---------|----------| | Available memory | > 20% of total | 10-20% | 50% |

Interpreting memory on Linux:

• "available" (not "free") is the true indicator of remaining capacity
• High "buff/cache" is normal and healthy — the kernel uses spare RAM for caching
• Swap usage above zero is not inherently bad, but heavy swap I/O indicates memory pressure

Interpreting memory on macOS:

• vm_stat reports in pages (typically 16384 bytes on Apple Silicon, 4096 on Intel)
• memory_pressure gives a simple "normal / warn / critical" assessment
• "Pages purgeable" and "Pages cached" are reclaimable — not a concern

Disk and filesystem

Review disk space, mount points, inode usage, and I/O throughput.

| Metric | Healthy | Warning | Critical | |--------|---------|---------|----------| | Disk usage | 90% | | Inode usage | 90% |

Common culprits for disk pressure:

• Log files (/var/log/, application logs)
• Build artifacts (target/, node_modules/, __pycache__/)
• Docker images and volumes
• Package manager caches

Processes

List running processes, identify top resource consumers, find specific processes by name or PID.

Useful views:

• Top CPU consumers (top 10 by CPU %)
• Top memory consumers (top 10 by RSS)
• Process tree (parent-child relationships)
• Zombie or defunct processes
• Processes by a specific user

Network

Inspect network interfaces, IP addresses, open ports, active connections, and routing.

Common checks:

• List interfaces and their IP addresses
• Show listening ports and the processes bound to them
• Display active connections (established TCP)
• Check DNS resolution
• Test connectivity to a remote host

Hardware

Retrieve details about physical hardware: CPU model, RAM modules, GPU, storage devices, USB peripherals.

Installed software

List installed packages, language runtimes, and key tool versions. Useful for environment replication and debugging compatibility issues.

Quick reference: cross-platform command map

| Task | Linux | macOS | Windows (PowerShell) | |------|-------|-------|---------------------| | OS version | cat /etc/os-release | sw_vers | Get-ComputerInfo | | Kernel | uname -r | uname -r | [Environment]::OSVersion | | Uptime | uptime | uptime | (Get-Date) - (gcim Win32_OS).LastBootUpTime | | CPU info | lscpu | sysctl -n machdep.cpu.brand_string | gcim Win32_Processor | | Memory | free -h | vm_stat | gcim Win32_OperatingSystem | | Disk space | df -h | df -h | Get-PSDrive -PSProvider FileSystem | | Top processes | ps aux --sort=-%cpu \| head | ps aux -r \| head | Get-Process \| Sort CPU -Desc \| Select -First 10 | | Open ports | ss -tlnp | lsof -iTCP -sTCP:LISTEN | Get-NetTCPConnection -State Listen | | Network IFs | ip addr | ifconfig | Get-NetIPAddress |

Output interpretation guidelines

When presenting results to the user:

1. Lead with the answer. State the key finding first ("Disk is 94% full on /"), then provide supporting data.
2. Use human-readable units. Always prefer GB/MB over raw bytes, percentages over absolute numbers where both are available.
3. Highlight anomalies. If any metric falls in the Warning or Critical range, call it out explicitly.
4. Provide actionable next steps. If disk is full, suggest what to clean. If a process is consuming excessive CPU, name it and suggest investigation commands.
5. Compare against baselines. When the user asks "is this normal?", use the threshold tables above as reference points.

Common troubleshooting patterns

System is slow

1. Check load average vs core count (CPU contention).
2. Check available memory and swap activity (memory pressure).
3. Check disk I/O wait (storage bottleneck).
4. Identify top CPU and memory consumers.

Out of disk space

1. Check df -h for filesystem usage.
2. Find largest directories with du -sh /* | sort -rh | head.
3. Check for large log files, build artifacts, and package caches.
4. Check inode usage (df -i) — many small files can exhaust inodes before space.

Process investigation

1. Find the process by name or PID.
2. Check its CPU and memory usage over time.
3. Examine open files and network connections (lsof -p PID).
4. Check parent process to understand how it was started.

Network connectivity issues

1. Check if the interface is up and has an IP address.
2. Test DNS resolution (dig, nslookup).
3. Test connectivity with ping or curl.
4. Check listening ports and firewall rules.
5. Review routing table for misconfigurations.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: bug-ops
• Source: bug-ops/zeph
• License: MIT
• Homepage: https://bug-ops.github.io/zeph/

Install and usage instructions live in the source repository linked above.