Ceph Cluster Diary March 2015

I am decommissioning all the USB backed OSDs. On the old hardware that I have the USB OSDs are much slower than USB spinning drives. With newer hardware I might get the full USB3.0 speeds that these flash drives are capable of. This does not mean I am done with Ceph. The truth is the complete opposite: I am migrating my bulk network storage to Ceph and so I need speeds comparable to my current RAID6 NAS box. This is why I have attached USB spinner drives: 2 x 2Tb, 1 x 1TB and 1 x 300Gb. Ceph reports I have just under 5Tb of usable space.

I will remove the netbook from the cluster because it’s too under powered for Ceph and I have other projects that can use it. That leaves a single older USB2 Toshiba Satellite to run Ceph until I get my two other planned nodes online. Those nodes are in decent sized tower cases with plenty of internal bays for more drives.

At present I’m not pressed for storage space. I backup the NAS to the Ceph cluster using rsync. That will do for now.

My future plans will be to consider an SSD based cache tier if I try another big data project. The speed I get from the object store will be the biggest driver of how much effort / budget goes in this direction.

I’m also watching developments in single board computers SBC. It’s almost getting cheap enough and maybe even powerful enough consider making an SBC running an OSD. Place an SBC and an HD into a stackable enclosure and there’s an easy way to grow out a home storage cluster a node at a time. If conditions are right I could even try placing a remote Ceph node or two at friend’s premises for automatic offsite redundancy over a VPN.

About those USBs: It was a great way to learn about Ceph for not much money. You could do the same thing with virtual machines and virtual devices I guess. But now – it’s time to be serious.