Red Hat Certified Specialist in Ceph Cloud Storage (EX260)

Finally, a new exam that contributes to RHCA in infrastructure track, bumping my level to XXIII.

EX260 hit GA on April 30th and I passed it just yesterday. Unlike EX125, which is based on Ceph 3, this one focuses on Red Hat Ceph Storage 4 and targets cloud-based containerized installations.

I didn't find it particularly challenging, but I noticed a few instances of where tasks could be more clear. But I expect it to improve over time as more people take it and offer their feedback. There is not much I can tell specifically about the exam without violating NDA, but CL260 course released shortly before the exam is very well structured and I found it very useful in preparing for the exam, even though you can always rely on exam objectives and official docs to be your guides.

There is something to be said about Ceph itself, even though the only instances when I ever used it on real projects were as a part of Red Hat OpenShift Container Storage, built on the backbone of Rooks (Ceph Kubernetes operator) and Noobaa (multi-cloud object gateway) projects. Ceph has a relatively steep learning curve when compared to simpler solutions, like GlusterFS, but it is much more flexible when it comes to data placement strategies and resilience. You can consume RADOS objects thorough numerous interfaces, depending on your data access patterns - filesystem, S3- and Swift-compatible API, block devices, or directly via librados library.

Another great feature of Ceph is client-side data lookup without reliance on a central lookup table which may hinder performance. Once you understand what placement groups are and how they map to OSDs, everything else is pretty easy to grasp. For me, being able to picture all this dynamics in my mind certainly helped.