Vmware Monitor

VMware Monitor (Read-Only)

Disclaimer: This is a community-maintained open-source project and is not affiliated with, endorsed by, or sponsored by VMware, Inc. or Broadcom Inc. "VMware" and "vSphere" are trademarks of Broadcom. Source code is publicly auditable at github.com/vmware-skills/VMware-Monitor under the MIT license.

Read-only VMware vCenter/ESXi monitoring — 32 MCP tools, zero destructive code.

Read-only toward vSphere: no code path changes vCenter/ESXi state — no power, create, delete, snapshot, or reconfigure call exists. On vCenter it opens only its login session and short-lived query handles it releases. Gate: tests/eval/regression/test_read_only_enforcement.py (source repo, not this bundle) requires every vSphere method called to be on a reviewed allowlist, checked against pyVmomi's type metadata. It checks source, not runtime, and no CI runs it. Independent of this code: use a dedicated account with vCenter's Read-Only role. Local writes (this machine only): init writes ~/.vmware-monitor/config.yaml and .env (0600; plaintext passwords are rewritten as b64: on load); audit logs ~/.vmware/audit.db (MCP) and ~/.vmware-monitor/audit.log (CLI); --html snapshots in ~/vmware-health/; after daemon start only, scan.log, daemon.pid and opt-in webhook posts. Companion skills: vmware-aiops (VM lifecycle), vmware-storage (iSCSI/vSAN), vmware-vks (Tanzu Kubernetes), vmware-nsx (NSX networking), vmware-nsx-security (DFW/firewall), vmware-aria (metrics/alerts/capacity), vmware-avi (AVI/ALB/AKO), vmware-harden (compliance baselines). | vmware-pilot (workflow orchestration) | vmware-policy (audit/policy)

What This Skill Does

Quick Install

uv tool install vmware-monitor==1.12.0
vmware-monitor doctor

When to Use This Skill

• List or search VMs, hosts, datastores, clusters
• Check active alarms or recent events
• Get detailed info about a specific VM
• Set up scheduled monitoring with webhook alerts
• Any read-only VMware query where safety is paramount

Alarm/Event Output: suggested_actions Field

get_alarms and get_events results include a suggested_actions list. Each item is a ready-to-use hint naming the correct companion skill and tool call (e.g. "vmware-aiops: acknowledge_vcenter_alarm(entity_name=..., alarm_name=...)"), so agents — especially smaller local models — can follow them directly without reasoning about skill routing. Example payload: references/capabilities.md.

Use companion skills for:

• Power on/off, deploy, clone, migrate --> vmware-aiops
• iSCSI, vSAN, datastore management --> vmware-storage
• Tanzu Kubernetes clusters --> vmware-vks
• Load balancing, AVI/ALB, AKO, Ingress --> vmware-avi

Related Skills — Skill Routing

Common Workflows

Diagnostic investigations: Before running any "why is X failing / down / abnormal" workflow, follow references/investigation-protocol.md. It enforces the four root-cause completeness criteria (falsifiability / sufficiency / necessity / mechanism) and the up-to-three-rounds deepening loop. Since vmware-monitor is read-only, it serves as the data source — actuation belongs to companion skills like vmware-aiops.

Cluster Health Check ("is anything on fire?" / "what's wrong right now?")

Judgment: this is the 5-second triage glance, not an Aria replacement. One call rolls every cluster's hosts, VM power, live CPU/memory and alarms up, flattens the individual anomalies into a ranked top-N focus list (top_issues), and gives each cluster an opinionated status. On a big fleet, lead with the focus list — scanning per-cluster rows is too slow.

1. One glance --> vmware-monitor summary (MCP: cluster_health_summary). Read top_issues first (worst first, each with a drill-down next step); the per-cluster table is context. issues_total shows how many anomalies existed before the top-N cap
2. Tighten or widen the focus --> --top 5 for the 5 most urgent, --top 20 for more, --top 0 to hide the list and just see the table
3. Drill into what the list points at --> e.g. a host_down row → inventory hosts; an alarm row → get_alarms; a capacity row → perf hosts / capacity datastores; scope with --cluster prod-a
4. Reshape the view on request --> the output ends with a friendly hint; the operator can say "add datastore free space", "drop the DRS column", "only show clusters needing attention", or "save this as an HTML page". Default layout, columns, and thresholds live in references/health-summary-template.md and are meant to be edited
5. Save an offline snapshot --> vmware-monitor summary --html writes a self-contained HTML file (no external assets, nothing uploaded) to ~/vmware-health/cluster-health-<vc>-<timestamp>.html; --html-path <file> for an explicit path. The timestamped filename means a folder of them becomes a browsable point-in-time history. It is a snapshot, not a live page — re-run to refresh
6. On a very large fleet --> add --no-vms to skip the VM rollup pass when you only need host/alarm/capacity signals
7. totals.clusters is 0 --> not empty: un-clustered hosts (standalone ESXi, or a cluster-less vCenter) form the (standalone hosts) row, still in totals and top_issues

Daily Health Check

Judgment: alarms tell you what vCenter has decided is wrong, events tell you what happened. They diverge — an event burst with no alarms often signals a metric threshold miscalibration, not "everything is fine." Read both.

1. Check alarms --> vmware-monitor health alarms --target prod-vcenter — focus on Red severity AND alarms older than 1 hour (transient ones self-clear)
2. Review recent events --> vmware-monitor health events --hours 24 --severity warning — look for repeated events from the same entity (a single event is noise; 50 events in an hour is a pattern)
3. List hosts --> vmware-monitor inventory hosts — flag hosts disconnected, in maintenance mode unexpectedly, or memory > 90%
4. If connection fails --> run vmware-monitor doctor to diagnose config/network issues

Object-Centered Investigation ("what is happening around this VM / host / datastore?")

Judgment: this is the drill-down the operator wants after triage points at a problem — one call correlates the object with its surrounding infrastructure and recent history, so you explain the aggregated result in operational language instead of stitching five tools yourself. The tool aggregates; you never dump raw inventory into the conversation.

Offer the levels progressively — do not ask for details the environment already fixes:

1. Start at the top --> cross_vcenter_attention (CLI: vmware-monitor attention) for "what needs attention now?" across every vCenter. If only one vCenter is configured, skip straight to its cluster_health_summary — no need to ask which target
2. Offer to drill into an object the top-issues list points at. Ask which level only when it is genuinely ambiguous:
   • a VM --> vm_investigation_bundle (CLI: vmware-monitor investigate vm <name>) → VM state, recent events, snapshots, alarms & recent changes, the host it runs on, the cluster context, the datastores backing it, performance signals, and a correlated event timeline
   • a host --> host_investigation_bundle (CLI: investigate host <name>) → host state, cluster context, the VMs it runs, mounted datastores, alarms, performance, correlated timeline
   • a datastore --> datastore_investigation_bundle (CLI: investigate datastore <name>) → capacity/free, mounting hosts, VMs it backs, alarms, correlated timeline
3. Widen or narrow on request --> --hours 72 for a longer event window; the bundle ends with a hint listing what is adjustable
4. Make it tangible --> add --html to any investigate/attention command for a self-contained offline snapshot (drill-down sections collapse/expand natively, no JS, nothing uploaded) written to ~/vmware-health/
5. If the object name is unknown --> the tool returns a teaching error naming exactly how to list the objects (list_virtual_machines / list_esxi_hosts / list_all_datastores); get the exact name and retry
6. If a vCenter is unreachable (attention only) --> it is listed under unreachable with a reason and the rest still aggregate — surface the gap, don't fail the whole view

Performance Triage ("the cluster feels slow")

Judgment: inventory shows configured capacity (cores, GB); it cannot tell you what is actually hot. Use the real-time perf tools, then narrow.

1. Rank hosts --> vmware-monitor perf hosts — the busiest host floats to the top (sorted by CPU%)
2. Rank VMs on the suspect --> vmware-monitor perf vms --limit 25 — find the noisy neighbour
3. Check for hidden storage pressure --> vmware-monitor capacity datastores — over-commit % > 100 means a thin datastore can fill mid-run even with "free" space showing
4. Rule out snapshot drag --> vmware-monitor snapshots aging --only-old — old snapshots silently degrade I/O
5. If perf tools return empty --> the host/VM may be disconnected or powered off (no real-time provider); confirm with inventory hosts / inventory vms

Scheduled-Outage Pre-flight (certs, licenses, time)

1. Cert expiry --> vmware-monitor infra certs --warn-days 60 — an expired ESXi cert drops host management
2. License headroom --> vmware-monitor infra licenses — catch over-allocation before it disables features
3. Time sync --> vmware-monitor infra ntp — healthy: no breaks SSO/Kerberos/log correlation (note: live offset is not exposed by the SOAP API, only config health)

Set Up Continuous Monitoring

1. Configure webhook in ~/.vmware-monitor/config.yaml
2. Start daemon --> vmware-monitor daemon start
3. Daemon scans every 15 min, sends alerts to Slack/Discord

Usage Mode

MCP Tools (32 — all read-only)

vSphere 9.1 field-parse honesty: the 3 REST tools' endpoints are spec-verified, but their JSON field names have NOT yet been replayed against a live 9.1 vCenter — every field is read defensively and each result self-labels via its note (endpoint verified; field parse best-effort pending live 9.1 vCenter). host_memory_tiering requires vCenter/ESXi 8.0U3+; older targets raise a teaching error naming the missing property.

No tool modifies, creates, or deletes any vCenter/ESXi resource. Performance/capacity readings are point-in-time samples — this skill retains no history, so it never reports a fabricated "trend" or runway date.

List result shape

The 21 row-listing tools above (including host_memory_tiering) return the family list envelope {items, returned, limit, total, truncated, hint}, not a bare array. Read truncated before summarising: true means more rows exist — never call items the whole picture; false means complete, so empty items means "checked, found none" — for host_log_scan, only if logs_unavailable (logs it could not read) is empty too. A null total (get_events, host_log_scan) is deliberate. Aggregate tools return purpose-built objects — see references/capabilities.md.

Read-Only by Design

All 32 tools are vSphere reads (local writes: see top). Running with local or small models? See references/agent-guardrails.md.

CLI Quick Reference

vmware-monitor summary [--top 10] [--cluster <substr>] [--html] [--target <t>]
vmware-monitor inventory vms|hosts|datastores|clusters|networks [--target <t>]
vmware-monitor health alarms|events|sensors|services [--target <t>]
vmware-monitor perf hosts|vms [--target <t>]
vmware-monitor capacity datastores|pools [--target <t>]
vmware-monitor infra certs|licenses|ntp [--target <t>]
vmware-monitor snapshots aging [--only-old] [--target <t>]
vmware-monitor vm info <vm-name> [--target <t>]
vmware-monitor memory tiering [--host <esxi>] [--target <t>]        # vSphere 9.1
vmware-monitor patch compliance|last-apply <cluster-moid> [--target <t>]   # vSphere 9.1 (vLCM)
vmware-monitor deployment-size [--target <t>]                      # vSphere 9.1
vmware-monitor scan now | scan logs [--host <name>] | daemon start|stop|status | doctor [--skip-auth]

Full CLI reference (all flags + activity/tasks/sessions): see references/cli-reference.md

Troubleshooting

Alarms returns empty but vCenter shows alarms

The get_alarms tool queries triggered alarms at the root folder level. Some alarms are entity-specific — try checking events instead: get_events --hours 1 --severity info.

"Connection refused" error

1. Run vmware-monitor doctor to diagnose
2. Verify target hostname/IP and port (443) in config.yaml
3. For self-signed certs: set verify_ssl: false

Events returns too many results

Use severity filter: --severity warning (default) filters out info-level events. Use --hours 4 to narrow time range.

VM info shows "guest_os: unknown"

VMware Tools not installed or not running in the guest. Install/start VMware Tools for guest OS detection, IP address, and guest family info.

Doctor passes but commands fail with timeout

vCenter may be under heavy load. Try targeting a specific ESXi host directly instead of vCenter, or increase connection timeout in config.yaml.

Should I set environment: on a read-only skill?

You can — add environment: production (or staging, lab, your own label) to each target in ~/.vmware-monitor/config.yaml. It's an optional label; this skill has zero write tools, so nothing it exposes is ever gated by it — reads are never gated. It matters for the write skills (vmware-aiops, vmware-storage, vmware-nsx) pointed at the same vCenter: an environment-scoped deny rule in ~/.vmware/rules.yaml can match on the label to block their writes (e.g. freeze production). A target with no label is simply not matched by such a rule. Config example: references/setup-guide.md.

Setup

uv tool install vmware-monitor==1.12.0
vmware-monitor init      # guided: prompts for host/user/password, writes config + .env (chmod 600), then verifies

init stores the password grep-safe (obfuscated b64:, never plaintext) and locks .env to 0600. Prefer it over hand-editing; manual steps: references/setup-guide.md.

Full setup guide, security details, and AI platform compatibility: see references/setup-guide.md

Audit & Safety

MCP tool calls are audited via vmware-policy (@vmware_tool); CLI commands append to ~/.vmware-monitor/audit.log:

• Every MCP tool call logged to ~/.vmware/audit.db (SQLite)
• Policy rules enforced via ~/.vmware/rules.yaml (deny rules, maintenance windows, risk levels)
• Risk classification: each tool tagged as low/medium/high/critical
• View recent operations: vmware-audit log --last 20
• View denied operations: vmware-audit log --status denied

License

MIT — github.com/vmware-skills/VMware-Monitor