Being a Ceph storage admin, maintaining your Ceph cluster will be one of your top priorities. Ceph is a distributed system that is designed to grow from tens of OSDs to several thousands of them. One of the key things required to maintain a Ceph cluster is to manage its OSDs. In this recipe, we will cover Ceph sub commands for OSDs and PGs that will help you during cluster maintenance and troubleshooting.
To understand the need for these commands better, let's assume a scenario where you want to add a new node to your production Ceph cluster. One way is to simply add the new node with several disks to the Ceph cluster, and the cluster will start backfilling and shuffling the data on to the new node. This is fine for a test cluster.
However, the situation becomes very critical when it comes to a production setup, where you should use some of the ceph osd
subcommands/flags, which are mentioned as follows, before adding a new node to the cluster, such...