About MongoDB Incremental Backup

Hi,

I’m encountering an issue while attempting to perform incremental/physical backups on my MongoDB server using PBM. Logical backups are working without any problems, and PITR is properly enabled and functioning.

However, when I try to initiate an incremental backup, PBM is unable to detect or communicate with the backup agents on the MongoDB server. Could you please help me identify if there is any misconfiguration or missing steps in my setup?

Looking forward to your assistance.

Thank you.

Hi, please check the pbm agent logs on all 3 servers of rs0.
journalctl -u pbm-agent

Hi Ivan,

I did not install pbm on prod servers. I have another server to take backups and I have created agent services to make connections to that servers.

When I check the agent logs, there are bunch of messages that says pitr is creating chunks.

image

pbm-agent@3.service log messages
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Hi berkan, pbm agent needs to be installed on the same servers as mongod process, otherwise it cannot get access to the mongo files. This is why you physical backup is failing.

So, I should delete those agents and install them on the rs0 servers, correct?

Once that’s done, I should be able to see the agents on my backup server, which I installed on the production servers, right?

yes, you don’t need a dedicated backup server that is external to the cluster. Install pbm agent on each rs0 node and that’s it.

Hi Ivan,

I have installed pbm-agents on server but it is trying to create directory for backups, but I wanted to take backups to the remote server that is not on prod servers.

Hi, pbm can take backups either to a S3-compatible storage, or to a shared volume that needs to be mounted on every server.
In this case you could export an NFS share from your backup server and mount that one every replica set member

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thank you, and also, mongodb community edition is a barrier right? i have to upgrade to the percona server.

Community edition does not expose backup cursor functionality needed for physical backups, so you need Percona distribution for that. Logical backups will still work though

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