Legacy migration to MongoDb Atlas

Yassine · 2025-03-11T18:40:43.174Z

Hello everyone,
I have a quite old Mongodb self hosted replica set with version: 3.4
I am researching how to migrate to a newer version on Mongodb Atlas.
According to the legacy migration docs here: https://www.mongodb.com/docs/atlas/legacy-migration/
and here: https://www.mongodb.com/docs/atlas/migration-live-atlas-managed/#std-label-live-migration-pre60
It is possible to pull data from my legacy replica set directly to a 6.0.17+ mongodb Atlas version, is my understanding correct?
Should I instead manually handle some edge cases that may arise or will the live migration do the work necessary?
Thanks for the help!

Michael_Lynn · 2025-03-11T18:42:10.315Z

Yassine, welcome to the community… Unfortunately, I don’t believe you can go directly from 3.4 to 6.+. I believe you need to step upgrade to 4.2 first…

Yassine · 2025-03-12T11:44:35.465Z

Alright.
What I was curious about is that the docs say you can use legacy migration tool to directly pull data to Mongodb Atlas 6.0.17+
Would this be possible then if I migrate first to 4.2?