Enterprise backup licensing scales painfully with data growth — per-front-end-TB, per-VM, or per-workload models compound every year. Open and lower-cost targets (Proxmox Backup Server, Bacula, Bareos, Restic) can dramatically cut recurring spend, but backup is a trust system: the migration is really about proving restores, not moving software.
What actually changes
Backups don’t “migrate” like VMs — you re-protect workloads on the new platform and let the old backups age out. Plan for:
- A clean policy inventory: protected workloads, schedules, retention, RPO/RTO, and offsite/immutable copies.
- New agents/integrations for each workload type (hypervisor, DB, file, application-consistent).
- A parallel-run window of at least one full retention cycle so you never have a coverage gap.
A safe flow
Deploy the new server, proxies, and repositories (including immutable/object storage), then run first full backups on the new platform while keeping the old repository read-only and retained. Run both in parallel, then switch primary schedules once you trust the new system.
Testing — the part that matters
Before trusting it, test restores, not just backups: file-level, full-VM, database, and a complete DR failover. Verify backup windows fit, dedup ratios are acceptable, and immutability/ransomware-recovery works end to end. Confirm RPO/RTO targets are actually met under realistic conditions.
Rollback discipline
Never delete the old backups on day one — retention and legal-hold obligations often require keeping them well past cutover. Keep the incumbent as primary until restores validate, then decommission on a schedule.
Open a source→target page for the specific re-baseline steps and a TCO model sized on TB protected.