Summary

In this chapter we learned about Ceph's internal components including Objects, the CRUSH algorithm, Placement Groups and pools and how they interact with each other to provide a highly reliable and scalable distributed storage cluster. We also harnessed our sandbox cluster to gain experience with interacting with these components. We also explored how data is stored within the cluster right from the point it entered in as a write request until it reached the correct OSD and was written on a storage device in the form of an Object file. We recommend that you try to repeat these examples on your test cluster to get a better idea of how Ceph replicates and stores data in a highly available fashion. If you are a system administrator, you should focus more on understanding how Ceph pools and CRUSH works as mentioned in this chapter. In the next chapter, we will learn how to provision a working Ceph Storage system.