Troubleshooting.
- August 6, 2019
Failed ESXi Upgrade: Recovering When Update Manager Goes Wrong
ESXi host upgrades via vSphere Update Manager (VUM, now Lifecycle Manager in newer versions) are routine operations that usually go smoothly. When they don’t, the failure modes can range from …
- May 14, 2019
VMFS Datastore Corruption: How It Happens and How to Recover
VMFS (VMware File System) is a clustered filesystem that lets multiple ESXi hosts access the same LUN simultaneously. It’s reliable, well-tested, and handles concurrent access through …
- January 22, 2019
Troubleshooting NSX-V: Controller Issues and What They Actually Mean
NSX-V’s control plane runs on a cluster of controller VMs that manage logical network state — VXLAN mappings, logical router tables, and distributed firewall rule distribution. When controllers …
- June 22, 2017
vCenter SSO: The Most Misunderstood Part of vSphere
vCenter Single Sign-On (SSO) is the authentication backbone of the vSphere platform. It handles login to vCenter, manages identity sources, and issues tokens that vSphere services use to authenticate …
- April 3, 2017
Stale Data After a Failed vCenter Upgrade: How to Clean It Up
A failed vCenter upgrade is among the more stressful VMware events you’ll deal with. The VMs are still running, HA and DRS are still functioning on cached state, but vCenter itself is in an …
- October 4, 2016
vCenter SSL Certificate Issues: The One That Bit Me Three Times
Certificate issues in vSphere environments are the most reliable source of annoying, hard-to-diagnose problems I’ve encountered. They show up at upgrade time, after hardware changes, when adding …
- May 18, 2015
XenServer Pool Master Failure: What Actually Happens and How to Recover
The pool master is XenServer’s single management control plane for a resource pool. All XenCenter connections, all xe CLI commands that operate across the pool, all pool-level configuration …
- August 22, 2014
Exchange 2013 Mail Flow Troubleshooting: A Methodical Approach
Mail flow issues are the highest-urgency Exchange problem category — users notice immediately when email stops working, and everyone assumes it’s the mail server’s fault even when …
- December 3, 2013
Exchange 2013 Managed Availability: Friend or Enemy?
Managed Availability is one of Exchange 2013’s most significant operational changes — and one of the least understood. It’s a built-in health monitoring and self-healing framework that …
- October 14, 2013
Exchange 2013 Database Troubleshooting: Dirty Shutdown and ESEUtil
At some point, you will open the Exchange Admin Center or EMS and find a database in a dismounted state. If you’re lucky, it’s a managed availability-triggered failover that resolved …