All posts
Legacy Modernization

Inventory a Legacy Estate in a Week: What to Collect, the Tools to Use, and What to Ignore

By

October 25, 2026

6 min read

Every modernization plan starts with the same question: what do we actually run? A one-week method for servers, databases, applications and the scheduled jobs and integrations nobody listed, using tools that are current in 2026 (Application Discovery Service and Migration Hub are now in maintenance).

Legacy Modernization
Inventory
Migration
Planning
AWS Systems Manager

Inventories fail by trying to be complete before being useful. The goal of week one is a list good enough to decide what to retire, what to upgrade in place and what to plan properly, with an owner against every line.

What to collect, per item

  • What it is: server, database, application, scheduled job, integration, file share.

  • Versions: OS, database engine, runtime and framework. These map directly onto end-of-support dates.

  • Owner: a person, not a team name.

  • Last real use: logons, queries, requests or job runs in the last 90 days.

  • Dependencies: what it talks to, from network connections rather than memory.

  • Cost: hardware, licences and cloud spend, even roughly.

Want a second opinion on this for your system?

Book a free 30-minute call. You'll leave knowing what we'd do first and roughly what it costs, whether or not you hire us.

Tools that are current

Need

Tool

Servers already on EC2

Systems Manager Inventory: OS, installed software, last logon

VMware estates

AWS Transform for VMware for discovery, dependency mapping and wave plans; or the VMware tools you already have

Network dependencies

VPC Flow Logs queried with Athena on AWS; NetFlow or firewall logs on-premises

Databases

Engine consoles and the database's own views of logins and queries

.NET and SQL Server applications

AWS Transform's assessment, which also sizes a port

Spend

Cost Explorer and the Cost and Usage Report, including Extended Support line items

AWS Application Discovery Service and AWS Migration Hub are in maintenance (closed to new customers) as of late 2025.

The week

  1. Day 1: export everything the tools above give you into one spreadsheet or table.

  2. Day 2: add versions and map each to its end-of-support date.

  3. Day 3: add last-use data and mark anything idle for 90 days as a retirement candidate.

  4. Day 4: interview owners for the top items by cost and risk; find the scheduled jobs and integrations that were not on any list.

  5. Day 5: sort into retire, upgrade in place, replatform and plan, and price the first wave.

hoolco Monthly Review

Once a month: what changed in tech that month and what it means for you, from cloud and AI to security and the tools you build with. Every item links to its source. No sales pitch, unsubscribe in one click.

As of October 25, 2026. Provided as is, for general information, and accurate to the best of our knowledge on the date shown. Not legal, compliance, tax, financial or other professional advice. Prices, limits and vendor services change; check current vendor documentation before relying on anything here. Terms of use.