Ceph & CentOS Updates: What it Means to You
* Shortly after we released this blog Red Hat made the decision to kill off CentOS 8. Check out this video where we explain more about this topic.
If you follow 45Drives, you’ve probably heard us mention Ceph – the premier open-source clustering software. Ceph links multiple storage servers together over a network to act as one large single unit. Ceph is robust, fully-featured, and production-ready, which is why we sell and support storage-systems built on Ceph open source software.
But, Ceph isn’t the only thing running on the servers in your storage system. Your clustered storage solution requires a Kernel and a local OS for Ceph to be built on – this is accomplished by using CentOS, the second most popular Linux distribution. Single servers purchased from 45Drives will by default use CentOS as its operating system.
Recently, we’ve finished getting ready to put the latest Ceph update (along with the newest release of CentOS) into production. These updates are not going to radically change the ways our customers interact with Ceph, but they will add some nice quality of life as well as performance improvements.
So, we figured we’d explain to the folks at home just what’s coming and what it will mean to them.
CentOS 8 – What’s new?
There are two big new updates for CentOS 8 that are highly relevant to its usage with Ceph:
- Kernel Update – CentOS 8 is built on the 4.18 Linux Kernel. This isn’t the absolute newest kernel, but it is a huge step up from 3.10 (CentOS 7’s kernel).
- Python 3 – CentOS 7 used Python 2.7.5, which has been updated to Python 3.6
We aren’t going to go too in-depth into the CentOS updates right now. Just know, this is a big step up kernel wise, and in order to get full functionality from the new Ceph update, you will need at least Python 3.
Ceph – Out with the Nautilus, in with the Octopus
Ceph Octopus brings a few changes customers will be able to use to make deploying and managing their Ceph cluster even easier. The big updates for Ceph are:
- Orchestrator API and CephADM
CephADM is the container-based deployment tool new to Octopus. Previously, the go-to Ceph orchestrator was Ceph-deploy, however, this is now being depreciated. There have been some other tools that leverage third-party software, such as, Ansible or Salt, which lead to community investment fracturing across the different tools. The goal of CephADM is to simplify and centralize common deployment and maintenance tasks. It gives an interactive CLI that can deploy a Ceph cluster more easily than was previously possible.
The Orchestrator API was released with Nautilus to allow some integration of Ceph’s CLI and GUI with the aforementioned deployment tools. It’s in a great spot now and allows you to spin up containerized Ceph services much more easily.
One caveat for CephADM is that it only supports Bluestor, which means you will not be able to use filestore OSD’s with CephADM. 45Drives solutions will still initially use Ansible, but we will look to leverage CephADM for certain containerization tasks.
- Dashboard upgrades
The dashboard has received a fair few changes and upgrades. We aren’t going to explain all the changes here (look for an update to our “Ceph Dashboard Walkthrough” in the near future). For now, here are some highlights:
- New Layout (vertical navigation bar)
- Better Background task and events notification (unified sidebar)
- Multi-select tables to perform bulk actions
- Security improvements for user accounts
- Disable user accounts without deleting them
- Inventory Page – shows all the storage devices in the cluster, and which OSD they are assigned. Has custom search functions for things like drive type, vendor, and capacity
- Define per-pool Quotas for both the amount of data in total or the number of objects that can be stored in a pool
All this information comes from this great talk about what’s new in this Ceph release, check it out if you are looking for more information.
There are some backend hiccups on upgrading existing systems to the newest Ceph update. We haven’t forgotten existing customers and are currently researching the safest and most efficient upgrade path for them. Stay tuned for more information on upgrades in the coming months.
45Drives systems are installed with CentOS 8, and for clusters, installed with Ceph Octopus as well. These new configurations have been tested and are thoroughly ready for production environments.
As always, if your use case requires you to run different software, 45Drives will be happy to work with your team to ensure you get a data-storage solution that is right for your environment.