Mongo Atlas storage size and index size 50% bigger than expected compared to on premise

Greetings.

We are wondering why your dataset in Mongo Atlas is almost 40% bigger than the dataset that we have on premise.

I have exported the dataset from atlas using mongodump and imported with mongorestore in our on premise environment and the difference is huge.

I had run the scripts found in https://github.com/tap1r/mongodb-scripts/blob/master/DB%20Storage%20tools.md#storage-engine-usage-reporting in both environments
to get some information.

Description:
Images where taken from MongoDB Compass after compacting (using db.runCommand({ compact: collectionname})) the collections.

On premise machines are running latest AWS Linux version with XFS filesystem, blocksize 4k and Mongo 7.0.1

Thanks

ATLAS CLUSTER



MONGO-ATLAS-DBSTAT-SCRIPT.txt (15.5 KB)

ON PREMISE



MONGO-ON-PREMISE-DBSTAT-SCRIPT.txt (9.8 KB)