The Tools Landscape
Every migration needs the right tool for each job — one to count what you own, another to lift the servers, another to move the databases without spilling a single row, and more to reshape apps for the cloud. This page is a friendly map of those tools, grouped by purpose rather than by brand. Then a picker lets you flip between AWS, Azure, and Google Cloud to see the real product names side by side.
Moving day is easier with the right gadgets: a clipboard to list every box, a dolly to roll heavy furniture, padded crates for the fragile stuff, a big truck for the online drive, and a shipping container when the truck is too slow. Migration tools are exactly those gadgets — just for servers, data, and apps instead of couches.
Why tools come in families
☺ Like you’re 10: You don’t use a hammer to wash dishes. Each moving-day job has its own gadget, and the gadgets come in matched sets.
No single tool does a whole migration. Instead, each cloud offers a family of tools, one per stage of the migration journey. Think of five big jobs that show up on almost every move:
- Discovery & assessment — count what you have, map how it connects, estimate the cost. This is Nutty’s “count before you pack.”
- Server / VM migration — copy running machines (a VM, or virtual machine, is a whole computer that lives as software) up to the cloud.
- Database migration — move the data that apps read and write, often while the app keeps running.
- Data transfer — bulk-move files and objects, either online (over the network) or offline (on a shipped appliance).
- Modernization / IaC / containers — reshape apps into modern forms and define the cloud setup as code.
The good news for beginners: once you learn these five buckets, every cloud looks the same. Only the product names change. That maps neatly onto the the 7 R’s — discovery tools help you decide a strategy, server tools handle rehost, and modernization tools handle replatform and refactor.
Meet the five tool families
☺ Like you’re 10: Five drawers in one toolbox. Here’s what each drawer is for and when you open it.
The diagram above names the five drawers; this section opens each one. For every family you’ll get the same two answers a beginner needs: what it’s for (the job it does) and when you reach for it (where it shows up in the migration journey). The product names come later — in the table and the picker below. Right now we’re learning the jobs.
1. Discovery & assessment
☺ Like you’re 10: Before you touch a single box, you count them all, label them, and draw lines showing what’s plugged into what.
What it’s for: you can’t move what you haven’t counted. Discovery tools scan your data center and build an inventory — every server, how big it is, how busy it runs, and which apps talk to which (the dependency map). Assessment adds judgement on top of the raw count: how ready each workload is for the cloud, how to size it, and what it will cost to run — the total cost of ownership (TCO).
When you reach for it: at the very start, in the assess phase, and again every time you plan a new batch of apps — discovery’s inventory and dependency map are exactly what wave planning groups apps from. This is Nutty’s “count before you pack,” and skipping it is how hidden dependencies break a cutover.
2. Server / VM migration
☺ Like you’re 10: The dolly that rolls a whole machine — still switched on — up to the cloud.
What it’s for: copying an entire server — a VM, or virtual machine, meaning a whole computer that lives as software — up to the cloud with its operating system, applications, and settings intact. The clever part is replication: the tool keeps copying changes while the original stays running, so the actual switch-over needs only a short window of downtime.
When you reach for it: when you want to move a machine as-is without rewriting it. This is the workhorse of a rehost (“lift and shift”) — the most common R for a first migration, and the fastest way to get out of an aging data center.
3. Database migration
☺ Like you’re 10: Padded crates for the fragile stuff — the data — so not a single row spills on the way.
What it’s for: moving the data an app reads and writes, usually while the app keeps running. Like server tools, database tools continuously replicate changes from the live source until the moment you cut over, so users barely notice. When the source and target database engines differ — say Oracle moving to PostgreSQL — a schema-conversion step first rewrites the structure (tables, keys, stored procedures) to fit the new engine.
When you reach for it: any time an application’s database has to move, and especially when that database can’t take much downtime. For the deeper story on keeping data safe and in sync, see data migration.
4. Data transfer — online vs offline appliance
☺ Like you’re 10: A big truck for the online drive — or a shipping container when the truck would be too slow.
What it’s for: bulk-moving plain files and objects — photo archives, backups, data lakes — rather than running machines or live databases. It comes in two flavors. Online transfer pushes the data over the network. Offline transfer ships you a physical, ruggedized appliance: you fill it up on-site, then mail it back for the cloud to load directly.
When is a truck faster than the internet? More often than beginners expect. If you have hundreds of terabytes and an ordinary network link, uploading could take weeks or months — longer than it takes to drive a hard-drive-packed box across the country. The rule of thumb: a steady trickle your bandwidth can handle goes online; a flood too big to push over the wire in reasonable time goes on the offline appliance. Choosing wrong — trying to shove 400 TB over office wifi — is a classic anti-pattern.
5. Modernization / IaC / containers
☺ Like you’re 10: Instead of just carrying the old furniture over, you rebuild some rooms smarter — and write the blueprint down so you can rebuild them anytime.
What it’s for: reshaping apps to fit the cloud better instead of moving them untouched — packaging them into containers (lightweight, portable boxes that hold an app and everything it needs to run), breaking a big app into smaller services, or shifting to managed platforms. Alongside sits Infrastructure as Code (IaC): writing the entire cloud setup as text files so it’s repeatable, reviewable, and rebuildable on demand instead of clicked together by hand.
When you reach for it: when a plain lift-and-shift isn’t enough and you want the cloud’s real payoff — scaling, resilience, lower running cost. These tools power the replatform and refactor R’s; the whole topic gets its own tour on the modernization page.
Every migration walks these five drawers in roughly this order: discover what you have, lift the servers, move the databases, transfer the bulk data, then modernize what deserves it. Learn the five jobs once and every cloud becomes readable — the table below is the at-a-glance recap, and the picker after it is the per-cloud detail.
The cross-cloud overview
☺ Like you’re 10: Same five gadgets, three different toy brands. Here they are lined up so you can see the matching pieces.
Read this table by row: pick a job on the left, then look across to see what each cloud calls its tool for that job. The names differ, but the jobs are identical everywhere.
| Purpose | AWS | Azure | Google Cloud |
|---|---|---|---|
| Discovery & assessment | Migration Hub + Application Discovery Service (both closed to new customers Nov 2025 — successor: AWS Transform); Migration Evaluator (TCO) | Azure Migrate (discovery + assessment) | Migration Center (with discovery client & assessment) |
| Server / VM migration | AWS Transform MGN (formerly Application Migration Service) | Azure Migrate: Server Migration | Migrate to Virtual Machines |
| Database migration | Database Migration Service (DMS) + Schema Conversion Tool | Azure Database Migration Service (DMS) | Database Migration Service (DMS) |
| Data transfer | DataSync (online) · Snowball (offline, retiring 2026) | AzCopy / Storage Migration (online) · Data Box (offline) | Storage Transfer Service (online) · Transfer Appliance (offline) |
| Modernization / IaC / containers | CloudFormation/CDK, EKS/ECS, App2Container, AWS Transform | Bicep/ARM, AKS, App Service | Migrate to Containers, GKE/Cloud Run, Config Connector |
Learn the five purposes, not the fifteen product names. When you land in any cloud, ask “which tool covers discovery? which covers databases?” and the rest falls into place. See the full-track walkthroughs on AWS, Azure, and Google Cloud.
Pick your cloud
☺ Like you’re 10: Choose one toy brand from the dropdown and you’ll see just its gadgets, with a one-line note on what each does.
Use the picker below to see one cloud’s toolset at a time, organized by the same five purposes. Watch for the online vs offline note under data transfer — online means “over the internet,” offline means “a physical appliance is shipped to you, filled, and mailed back.”
- Discovery & assessment: AWS Migration Hub tracks progress in one dashboard and Application Discovery Service inventories on-prem servers and their dependencies — both closed to new customers since Nov 2025, with AWS Transform as the successor; Migration Evaluator estimates cost and total cost of ownership (TCO).
- Server / VM migration: AWS Transform MGN (formerly AWS Application Migration Service) — the standard lift-and-shift tool that replicates whole servers into AWS (it replaced the retired Server Migration Service).
- Database migration: AWS Database Migration Service (DMS) moves databases with little downtime; the Schema Conversion Tool (SCT) rewrites schemas when the source and target engines differ.
- Data transfer: AWS DataSync for online file/object transfer over the network; AWS Snowball — now retiring (closed to new customers Nov 2025; support ends Dec 2026; AWS points new bulk moves to DataSync and its Data Transfer Terminal locations) — historically the offline answer on a shipped, ruggedized appliance when the network is too slow.
- Modernization / IaC / containers: CloudFormation and the CDK define infrastructure as code; Amazon EKS/ECS run containers; App2Container containerizes existing apps; AWS Transform assists refactoring.
- Discovery & assessment: Azure Migrate is the unified hub — it discovers servers, databases, and web apps, then assesses readiness, sizing, and cost before you move.
- Server / VM migration: Azure Migrate’s Migration and modernization tool (formerly “Server Migration”) replicates on-prem or other-cloud VMs into Azure (built on Azure’s replication technology).
- Database migration: Azure Database Migration Service (DMS) moves SQL Server, MySQL, PostgreSQL, and MongoDB; the migration experience built into SQL Server Management Studio (SSMS) guides SQL moves (its predecessors — Data Migration Assistant and the Azure Data Studio migration extension — were retired in 2025–2026).
- Data transfer: AzCopy and storage migration tools for online transfer; Azure Data Box for offline bulk transfer (tens to hundreds of terabytes) on a shipped appliance.
- Modernization / IaC / containers: Bicep and ARM templates (or Terraform) for infrastructure as code; Azure Kubernetes Service (AKS) for containers; Azure App Service for replatformed web apps.
- Discovery & assessment: Migration Center is the central hub — its discovery client inventories your estate and its assessment features size workloads and estimate TCO.
- Server / VM migration: Migrate to Virtual Machines lifts VMs from vSphere, AWS, or Azure into Google Cloud (offered at no charge for inbound migrations).
- Database migration: Database Migration Service (DMS) handles same-engine and cross-engine moves — MySQL, PostgreSQL, SQL Server, Oracle — into Cloud SQL or AlloyDB.
- Data transfer: Storage Transfer Service for online transfer into Cloud Storage; Transfer Appliance for offline bulk transfer (recommended above ~20 TB, up to a petabyte).
- Modernization / IaC / containers: Migrate to Containers turns VMs into container workloads; GKE and Cloud Run run them; Config Connector and Terraform define infrastructure as code.
Tool names change over time — vendors rename, merge, and retire services (for example, AWS Server Migration Service was folded into Application Migration Service, and DMS Fleet Advisor is being discontinued in 2026). Always double-check the current official docs before you build a plan on a specific product name.
Foxy: Benny, there are so many tools! How do I even know which one to grab?
Benny: Start with the job, not the name. Moving a whole server? Reach for the server-migration drawer. Moving a database? That’s Ellie’s DMS drawer.
Nutty: And before any of that — you call me! Nothing moves until discovery has counted every box and mapped what’s plugged into what.
Gizmo: Ugh, counting is slow. Just download 400 terabytes over the office wifi tonight — one big tool, done by morning!
Ellie: Four hundred terabytes over wifi? That’s a ship-the-appliance job, Gizmo — an offline transfer box, not the online pipe. You’d still be uploading at Christmas.
Timmy: Fact-check: right gadget for the right job beats one heroic tool every time. Online for the trickle, offline appliance for the flood.
Pick one cloud from the picker. For each of the five purposes, write down the tool name and one sentence on what it does. Then answer: which two tools would you use to move a 500 TB file archive plus a live PostgreSQL database with minimal downtime? (Hint: one offline transfer tool, one database tool.)
Online transfer is for a steady trickle your network can handle; an offline appliance is for a flood too big to push over the wire in reasonable time. Choosing wrong is a classic anti-pattern — see also data migration and best practices.
1. What are the five tool purposes every cloud provides a tool for? 2. Which purpose does “count before you pack” belong to, and who’s its host? 3. What’s the difference between an online transfer tool and an offline appliance? 4. Name one AWS, one Azure, and one Google Cloud database migration tool.
Check your answers
- Discovery & assessment; server/VM migration; database migration; data transfer; and modernization / IaC / containers.
- Discovery & assessment — hosted by Nutty the Squirrel, the Scout who inventories and maps dependencies before anything moves.
- Online tools push data over the network (good for a trickle your bandwidth can handle); offline appliances are physical boxes shipped to you, filled, and mailed back (good for floods of data too large to send over the wire).
- AWS Database Migration Service (DMS); Azure Database Migration Service (DMS); Google Cloud Database Migration Service (DMS) — each pairs with schema tools when engines differ.