Unable to start mongodb 3 node replicaset

We have a 3 node replicaset mongo v4.4.1 running in kubernetes… mongodb-0 is not starting up with below error

Failed to start up WiredTiger under any compatibility version. This may be due to an unsupported upgrade or downgrade​​
Fatal assertion","attr":{​​​​​​​"msgid":28559,"file":"src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp","line":64
***aborting after fassert() failure
Writing fatal message","attr":{​​​​​​​"message":"Got signal: 6 (Aborted).

we upgraded from 3.6.4 to 4.4.1 a while ago. everything was working fine… then after few deployments we are getting “Failed to start up WiredTiger under any compatibility version” now. not sure what happened.

gist of mongo logs

any help would be greatly appreciated.

  • vineet

Hi @Vineet_Bhatia

You have likely neglected to upgrade the feature compatibility level during your upgrades from 3.6 thru 4.4.1

Mongod should have written out the last version that successfully ran your database. Check this post for some information on that. How to check mongo version from volumes that I've set in the docker-compose.yml file? - #2 by chris

Once you get it running change the FCV as per the upgrade guide for the version running. This is found in the release notes section of the manual.

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