Priority: Major - P3
Affects Version/s: None
Fix Version/s: None
Last comment by Customer:true
As per the AWS docs:
Initializing Amazon EBS Volumes,
For a new volume created from a snapshot, you should read all the blocks that have data before using the volume.
If the volumes are not initialised, it may take several minutes to several hours for the mongod instance to start.
This generally affects MongoDB 3.2 with WiredTiger which samples the oplog while starting (see SERVER-19551). However, it should be better to have the volume initialised in all versions as the data anyways has to be read from disk and the process will be slow for uninitialised volumes.
Information regarding this behaviour should be good to have in either of these MongoDB docs: