Hi, I just tried to upgrade my Atlas cluster from MongoDB 4.4 to 5.0 after it was advertised to me, but got the message “The version cannot be changed for M0 clusters”. So I upgraded to M2, and got the message “The version cannot be changed for M2 clusters”
What type of clusters can I change the version for? I’m not sure I need more than M0 for my current project, apart from the desire to upgrade to the latest version of MongoDB.
Thanks
Hi @Shea_Dawson,
Welcome to the community!
MongoDB version 5.0 is not currently available on M0,M2 and M5 tier clusters. You’ll need an M10 tier or higher in Atlas to upgrade to 5.0.
I understand you won’t require higher than M0 for your current project so a temporary alternative may be to use MongoDB Community Server where version 5.0 is available for download.
Kind Regards,
Jason
Hi Jason, thank you for clarifying that for me.
I was interested in the time series collections introduced in 5.0 but now realise they are not compatible with Realm Sync anyway so I have no reason to upgrade to 5.0. Do you know if there are any plans to support Realm Sync time series collections?
I’d now live to downgrade from M2 back to M0 but can’t see a way to do that. Is it not possible?
Thanks again 
Hi @Shea_Dawson,
Do you know if there are any plans to support Realm Sync time series collections?
Unfortunately I don’t have any information on this question.
I’d now live to downgrade from M2 back to M0 but can’t see a way to do that. Is it not possible?
You won’t be able to downgrade from an M2 to an M0. You’ll need to use mongodump to create a BSON file of your cluster and then a mongorestore to restore the data to a M0 tier cluster. You can use the Command Line Tools tab to assist you with using these tools to connect to your Atlas cluster(s).
Hope this helps.
Kind Regards,
Jason