VMware — operating memo

Confirms build before comparing compatibility or KBs.

Powerful interactive tool; use carefully and quit with q.

Shows vendor, model and host UUID.

Checks ESXi services and startup policy.

Shows VMID, datastore and VMX path.

Confirms state without vCenter.

Depending on version, provides guest/tools information.

Correlate migrations, snapshots, resets or errors with incident time.

Checks snapshot presence and hierarchy.

Old snapshots can grow and hurt storage/performance.

Do not manually delete delta VMDKs.

Consolidation can create significant I/O load.

Shows capacity, free space, type and mount state.

A full datastore can break snapshots, VMs and consolidation.

Checks NFS mounts.

Maps VMFS datastores to devices/partitions.

Shows devices, model and status.

Checks active/dead paths and multipathing.

Lists storage adapters.

Look for APD/PDL, path failures and latency.

Checks link, speed, duplex and driver.

Shows vmkernel IP configuration.

Checks gateways and static routes.

Tests from a specific VMkernel interface.

Storage, networking, drivers and kernel.

Local host management and VM operations.

Communication between ESXi and vCenter.

Authentication and shell access depending on version.

Do not confuse VMware snapshots with backups.

Ensure the cluster can absorb host evacuation.

Blocked vMotion can prevent maintenance mode.

Address pre-existing alarms before creating a new event.