With cloud storage becoming more and more important for business nowadays due to the massive growth in the scale of unstructured data, organizations or enterprises are replacing their traditional storage to cloud storage gradually. In order to have a highly reliable and scalable storage, the perfect open source storage solution for such scenario is the adoption of Ceph.
Unlike traditional storage solutions, such as DAS and NAS which suffer from limited scalability or vendor lock-in, Ceph is cost-effective, meaning it is designed to run on commodity hardware with scalability in mind.
Figure 2 illustrates the difference between Ceph and traditional storage. Ceph can scale vertically, but also it can scale horizontally if needed. By adopting Ceph, users can build a small-scale storage system in the beginning phase of a project, then scale the storage nodes one after one later on.
Furthermore, users can configure the desired number of copies/replicas in the storage, which enables it to have powerful data reliability. By default, three replicas of Ceph provide 99.9999999% data reliability, which is a lot better than what the traditional NAS storage can offer.
Additionally, Ceph uses CRUSH algorithm to determine where to store and retrieve the copies in a storage cluster. All calculations are performed on the client side rather than on the server side. This feature cannot be accomplished by utilizing traditional storage system.
From the perspective of application, Ceph provides three access methods shown in Figure 4.
The three access methods include RBD, CephFS, and RadosGW, which handle object, block, and file respectively. Compared to traditional storage system, Ceph delivers better flexibility, and can allocate resources if required.
Because of the above-mentioned characteristics, organizations and enterprises, such as CERN(Conseil européen pour la recherche nucléaire), Yahoo, NewEgg, and Academia Sinica, all adopt Ceph to be their storage system solution. No doubt about it that Ceph becomes one of the best storage solutions for now.
撰文： 傅遠佳 迎棧科技資深架構師