Reference
Sendense Controllers
Per-VM DR target appliances used by controller-backed replication patterns.
Definition
Sendense Controllers are target-side per-VM destination appliances used by controller-backed replication workflows.
Customers do not pre-provision controller VMs. The destination system must have the required controller template available, and Sendense provisions controller VMs on demand as protected VMs are added to replication patterns.
What Controllers Do
A controller VM is created from the controller template in the destination system. It has its own management operating system disk and carries the attached replica data disks for its protected workload.
- Prepare and maintain the replication target for one protected VM.
- Offload target-side preparation and conversion work for that VM.
- Handle target-side disks for the replicated workload.
- Provide recovery readiness and validation signals.
- Support test failover, planned failover, live failover, commit, rollback, and guest adaptation where applicable.
- Report controller health, network reachability, version, and disk health back to the Sendense control plane.
Scaling Model
Sendense uses one controller VM per protected VM. This offloads target-side preparation and conversion work to the controller, allowing replication and failover work to scale horizontally.
One controller per protected VM
The target SNA is the shared replication ingress for the recovery site. Each protected VM has its own Sendense Controller holding its replica disks, so target-side work scales with the workload count.
How Replication Data Reaches A Controller
Replication data reaches a controller through the SNA at the recovery site. On every replication route, the recovery-site SNA receives the replication stream and passes it to the controller for that VM, and that controller traffic stays inside the recovery site.
Controllers also report health and readiness back to the Sendense control plane. In some deployment shapes, controller heartbeat and control traffic can flow through an SNA relay; in local or cohosted deployments it can flow directly to SHA.
Controller Lifecycle
A controller-backed target moves through operational states: provisioning and initializing while Sendense prepares the controller, then ready with syncs running on schedule (and paused where an operator disables them). Failover moves the target through the failover lifecycle: a test failover is rollback-eligible, and a live failover awaits commit or rollback. After commit, the promoted VM is production and the target leaves normal replication management.
During Failover
During failover, Sendense promotes and boots the existing controller-backed target rather than creating a recovered VM from scratch. During replication, a controller defaults to 2 vCPU and 4 GB RAM; during failover, the promoted workload switches to the protected VM compute specification where supported.
Controllers And Other Sendense Roles
Sendense Controllers participate in DR failover operations, not ordinary full VM restore from EBA.
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