Closing a datacenter is a cost decision before it is a technical one. Ours was a colocation site, space we rented in someone else’s building, and it had changed hands several times over the years. Each new owner brought a new pricing structure, and the cost of staying there was climbing fast enough that keeping our hardware in that room had stopped making sense.

Over about five years I ran multiple rounds of VMware host replacement and vSphere upgrades across our multi-site environment, and I did all of it during normal business hours with zero impact to the workloads running on top. Each round covered roughly 10 to 25 hosts at a time, full hardware refreshes, major-version ESXi and vCenter upgrades, and SAN refreshes running in parallel.