VMware ESXi Host Operations

Manage and inspect VMware ESXi hypervisors in the pyATS testbed using pyats_run_linux_command . This skill covers VM inventory listing and snapshot inspection using the ESXi vim-cmd interface.

Testbed Requirements

ESXi hosts must be defined in the pyATS testbed with os: linux (ESXi shell is Linux-based):

devices: esxi-host-01: os: linux type: esxi connections: cli: protocol: ssh ip: 10.0.0.100 port: 22 credentials: default: username: "%ENV{NETCLAW_USERNAME}" password: "%ENV{NETCLAW_PASSWORD}"

Note: SSH must be enabled on the ESXi host (disabled by default). Enable via vSphere Client → Host → Configure → System → Services → SSH → Start.

How to Call

All commands use pyats_run_linux_command :

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_linux_command '{"device_name":"esxi-host-01","command":"<command>"}'

Commands

VM Inventory

List All Virtual Machines

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_linux_command '{"device_name":"esxi-host-01","command":"vim-cmd vmsvc/getallvms"}'

Returns a table of all VMs on the ESXi host:

Column Description

Vmid Unique VM identifier (used as parameter for other vim-cmd operations)

Name VM display name

File Path to the VMX configuration file on the datastore

Guest OS Configured guest OS type (e.g., ubuntu64Guest , windows9Server64Guest )

Version Virtual hardware version (e.g., vmx-19 , vmx-20 )

Annotation VM description/notes

What to check:

• All expected VMs are present and registered

• VMX file paths reference expected datastores

• Virtual hardware versions are current (old versions may lack features)

• Guest OS type matches actual installed OS

• No orphaned or unexpected VMs

Snapshot Management

Get VM Snapshots

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_linux_command '{"device_name":"esxi-host-01","command":"vim-cmd vmsvc/snapshot.get 1"}'

The parameter is the Vmid from vim-cmd vmsvc/getallvms . Returns the snapshot tree for that VM:

• Snapshot name and description

• Snapshot ID

• Creation timestamp

• Whether it's the current snapshot (the "you are here" marker)

• Parent/child snapshot hierarchy

What to check:

• Stale snapshots — snapshots older than 72 hours degrade performance (growing delta disks)

• Snapshot chains — deep chains (>3 levels) cause I/O performance degradation

• Pre-change snapshots — verify a snapshot was taken before maintenance windows

• Disk space — snapshot delta files consume datastore space proportional to guest write activity

Workflows

1. VMware Inventory Audit

pyats_list_devices → identify ESXi hosts in testbed → vim-cmd vmsvc/getallvms per host → collect all VMs → Cross-reference with NetBox/Nautobot → flag undocumented VMs → Check virtual hardware versions → flag outdated versions → GAIT

2. Snapshot Health Check

pyats_list_devices → identify ESXi hosts → vim-cmd vmsvc/getallvms per host → get VM IDs → vim-cmd vmsvc/snapshot.get per VM → collect snapshot trees → Flag: snapshots > 72 hours old, chains > 3 deep, orphaned snapshots → Severity-sort (stale snapshots = WARNING, deep chains = CRITICAL) → GAIT

3. Pre-Change VM Verification

ServiceNow CR must be in Implement state → vim-cmd vmsvc/getallvms → identify target VM by name → get Vmid → vim-cmd vmsvc/snapshot.get {vmid} → verify pre-change snapshot exists → If no snapshot: STOP — snapshot must be taken before changes → Record baseline state in GAIT

4. Multi-Host VM Inventory

pyats_list_devices → identify all ESXi hosts → vim-cmd vmsvc/getallvms per host (parallel) → collect fleet-wide VM inventory → Aggregate: total VMs, VMs per host, hardware version distribution → Cross-reference with vCenter inventory (if available) → GAIT

Parallel Operations

Run VM inventory across multiple ESXi hosts concurrently:

ESXi Host 1

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_linux_command '{"device_name":"esxi-host-01","command":"vim-cmd vmsvc/getallvms"}'

ESXi Host 2

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_linux_command '{"device_name":"esxi-host-02","command":"vim-cmd vmsvc/getallvms"}'

ESXi Host 3

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_linux_command '{"device_name":"esxi-host-03","command":"vim-cmd vmsvc/getallvms"}'

For snapshot checks, first collect VM IDs per host, then run snapshot queries in parallel across all VMs.

vim-cmd Quick Reference

Command Description

vim-cmd vmsvc/getallvms

List all registered VMs (ID, name, file, OS, version)

vim-cmd vmsvc/snapshot.get {vmid}

Get snapshot tree for a specific VM

vim-cmd vmsvc/power.getstate {vmid}

Get VM power state (on/off/suspended)

vim-cmd vmsvc/get.summary {vmid}

Get VM summary (CPU, memory, tools status)

Note: Only getallvms and snapshot.get are covered by this skill. The reference above is for context — expand to other vim-cmd operations as needed.

Integration with Other Skills

Skill Integration

pyats-linux-system System-level commands on the ESXi host (ps, ls, docker stats)

pyats-linux-network ESXi host networking (interfaces, routes) — useful for vmkernel adapter inspection

pyats-network Network device show commands complement ESXi host-level views

pyats-parallel-ops pCall pattern for fleet-wide ESXi operations

netbox-reconcile Cross-reference VM inventory with NetBox virtualization records

nautobot-sot Validate ESXi host and VM data against Nautobot

servicenow-change-workflow Gate snapshot operations behind ServiceNow Change Requests

gait-session-tracking Every vim-cmd execution logged in GAIT

nvd-cve Check ESXi versions against NVD vulnerability database

cml-lab-lifecycle CML labs may run on ESXi — correlate VM inventory with CML topology

Guardrails

• Always call pyats_list_devices first — verify ESXi hosts exist in the testbed

• Read-only operations only — getallvms and snapshot.get are read-only

• Never create/delete snapshots via this skill — snapshot creation/deletion impacts VM performance and requires a ServiceNow CR

• Never power-cycle VMs — vim-cmd vmsvc/power.* operations are destructive and require explicit authorization

• Validate Vmid before use — always get the Vmid from getallvms output; never guess or hardcode

• Flag stale snapshots — any snapshot > 72 hours should be flagged as WARNING; > 7 days as CRITICAL

• SSH access concerns — ESXi SSH is often disabled in production; document that it must be enabled for pyATS access

• Record in GAIT — every vim-cmd execution must be logged