Who this is forInfrastructure managers and IT directors with a server move in prospect, who want to know whether they are ready to schedule it and where the gaps are.
This is a rule-based planner. You answer seven groups of questions about your own estate, and it returns a readiness level, a worked transfer-time calculation, a suggested sequence, the risks your answers raise, a rollback outline and a cutover checklist. It does not recommend a supplier, quote a price or promise an outcome.
What it is not. It has not looked at your servers, network or applications, and it cannot. It is not an audit, a scan, a test or a certification, and its output is a planning aid built entirely from the answers you type. If you give it optimistic answers it will give you an optimistic plan.
Your data stays in your browser. The calculation runs in JavaScript on this page. The page makes no network requests with your answers, stores nothing in cookies or browser storage, and has no server component to receive them. Closing the tab discards everything. If you copy the summary out, what happens to it next is up to you.
How the planner decides
Five factors are scored: inventory (0 to 3), dependencies (0 to 3), rollback (0 to 3), DNS and addressing (0 to 2), and how well the estimated outage fits your tolerance (0 to 3). The outage estimate comes from your data volume, change rate and link speed through the arithmetic shown in the result. The total is out of 14, and then five gates apply, each of which can only lower the level:
- An inventory or dependency picture below “verified” caps the result at discovery first, whatever else you scored.
- An estimated outage more than one and a half times the tolerance caps it at re-plan the cutover method.
- No rollback plan at all, or a total below 8 of 14, caps it at significant gaps.
- A total below 11, or a rollback plan that is not yet written down, caps it below the top level.
- Only the top level says ready to schedule a rehearsal and a cutover window. It never says the migration will succeed.
The gates are deliberately blunt. A worse answer never improves the result, and a good score elsewhere cannot buy back a missing inventory.
The transfer arithmetic, by hand
You can check the calculator without it. One gigabyte is 8 billion bits, or 8,000 megabits. Divide the data in megabits by the usable rate in megabits per second to get seconds.
| Data | Link | Usable share | Arithmetic | Time |
|---|---|---|---|---|
| 1 TB | 1 Gbit/s | 100% | 1,000 x 8,000 / 1,000 = 8,000 s | 2 h 13 min |
| 1 TB | 1 Gbit/s | 70% | 8,000,000 / 700 = 11,429 s | 3 h 10 min |
| 10 TB | 1 Gbit/s | 80% | 80,000,000 / 800 = 100,000 s | 1 d 3 h 47 min |
| 500 GB | 100 Mbit/s | 100% | 4,000,000 / 100 = 40,000 s | 11 h 7 min |
Why the usable share is below 100%: encryption, protocol overhead, many small files, latency on a single stream and other traffic on the same path all cost throughput. The server migration guide works through a case where a gigabit link delivers a fraction of its nominal rate because of round-trip time.
Where to go next
If the planner says discovery first, start with the discovery section of the server migration guide. If it says the method does not fit, compare it with the target in the architecture comparison matrix. If rollback is the gap, read the recovery sections of backup, high availability and disaster recovery.