In a typical vCenter Server upgrade, the vCenter Server itself requires multiple reboots, leading to an unacceptable interruption in management access, monitoring, and automation capabilities.
Challenge of the Traditional Upgrade
In older versions, upgrading vCenter was a sequential, disruption process:
- The vCenter VCSA appliance would deploy a temporary target appliance.
- Data synchronization occurred.
- A major service interruption happened during the final cutover, including multiple reboots of the vCenter appliance.
While the data plane (VM workloads) remained unaffected, the loss of the control plane meant no monitoring, no vMotion, no API access, and no operational changes could occur during this window.
vCenter Reduced Downtime Upgrade (RDU), performs a migration-based approach to update vCenter Server.
Key Pointers:
- he RDU process is designed to synchronize data between the source (old) and target (new) vCenter appliances while both are running.
- The actual cutover phase—where the network identity is switched from the old vCenter to the new one—is reduced to the time it takes for a few network operations (around 2-5 minutes). This is a dramatic reduction from the 30-60+ minutes previously required for reboots and service restarts.
- We can schedule the switch over from the source vCenter to the target vCetner as part of the RDU Process.
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