Mongod service failing to start

[Arkadiusz_Borucki (Arek Borucki)]

if you upgrade the mongod binaries you can not upgrade directly from 3.4 to 4.2. it is always better to follow official MongoDB documentation, also there was a similar topic - please read:

How to upgrade from v3.6.3 to v4.4.5?

Hi @mental_N_A, You have multiple solutions to upgrade from MDB 3.6 to 4.4. But before you try anything BACKUP EVERYTHING and of course make sure that you can recreate a 3.6.3 node from your backup so you can always come back and try something else. The dump solution mongodump & mongorestore can backup and restore entire databases in a MongoDB cluster. The BSON file they create might not be compatible if the gap between your MongoDB versions is too large (like 2.4 to 4.4 for example). But be…