Finding VM File Locks on ESXi: A Production-Safe Runbook Before You Kill Processes

A virtual machine file lock issue rarely shows up at a convenient time. It usually appears when a VM refuses to power on, a consolidation task is stuck, a backup window has overrun, or vCenter and an ESXi host disagree about the VM’s state. That is exactly when bad habits get expensive. The temptation is … Read more

ESXi PSOD Triage: Turning a Purple Screen into an Evidence-Driven Escalation

A purple screen on an ESXi host creates an immediate operational problem, but the bigger risk is what happens next. The first reaction is usually to get the host back online. That is understandable, especially when workloads are down, HA is recovering virtual machines, or a cluster is running hot after losing capacity. But if … Read more

When Fibre Channel Paths Lie: A Safe Fabric Login Reset Runbook for ESXi

There are storage incidents where the host looks half-recovered. The fabric switch is back online. The link light is good. The array port is healthy. Some paths may even show up again. But inside ESXi, the storage view still does not match reality. A datastore has fewer paths than expected. An RDM-backed workload is not … Read more

VLAN Design Translation for VMware: Physical Trunks, Port Groups, and Guest Tagging

VLAN issues in VMware environments are rarely caused by one mysterious setting. More often, they come from a translation problem. The network team thinks in terms of access ports, trunks, allowed VLAN lists, native VLANs, port channels, and upstream gateways. The virtualization team thinks in terms of vSwitches, distributed port groups, VMkernel adapters, VM network … Read more

DVS Upgrade Guardrails: What Can Break When Old Distributed Switches Move Forward

A vSphere Distributed Switch upgrade can look deceptively simple in the vCenter UI. Select the switch, choose the target version, confirm the warning, and move on. That is not how it should be treated in a brownfield environment. The risk is not that a DVS upgrade is always dangerous. The risk is that old distributed … Read more

VM Network Troubleshooting from Guest OS to Uplink: A Layer by Layer VMware Runbook

Virtual machine network problems rarely arrive with a clean label. The ticket usually says something like “the VM is unreachable,” “the application cannot connect,” “ping fails,” “internet access is down,” or “VMs on different hosts cannot talk.” The underlying cause might be inside the guest OS, on the VM’s virtual NIC, in the port group, … Read more

PDL vs APD: The Storage Failure Model Every vSphere Operator Needs

Storage failures in vSphere are rarely just “storage is down.” That phrase may be accurate from the application owner’s point of view, but it is not precise enough for the operator who has to decide what happens next. A host that has lost all paths to a datastore behaves differently from a host that has … Read more

Why Large VM vMotion and Clone Tasks Fail: Device Limits, Config Hygiene, and PowerCLI Prechecks

Large VM migrations usually fail at the worst possible time: late in the change window, after the task has already consumed hours of storage, network, and operator attention. When the error is something like “Invalid configuration for device ‘##’,” the first instinct is to look for a broken virtual NIC, a missing port group, an … Read more