So sánh giải pháp storage giữa Gluster vs Ceph Cloud Storage

So sánh giải pháp storage giữa Gluster vs Ceph Cloud Storage

The open source cloud storage war is here, and show no sign of stopping soon.
Two major competitors are GlusterFS and Ceph. Both wanted to become the distributed scale-out storage software of choice for OpenStack.
Lets try to understand some basic differences between GlusterFS and Ceph.
They are rivals in the same space, but they too have got some similarities.
1. Both have common enemies in the form of proprietary big storage
2. They genuinely like each other.
Now comes some differences.

CEPH – Ceph is at base an object-store system, called RADOS, with a set of gateway APIs that present the data in block, file, and object modes. The topology of a Ceph cluster is designed around replication and information distribution, which are intrinsic and provide data integrity. Ceph is an open-source, massively scalable, software-defined storage system which provides object, block and file system storage in a single platform. It runs on commodity hardware—saving you costs, giving you flexibility—and because it’s in the Linux kernel, it’s easy to consume.
Ceph has been developed from platform that is self-managing, self-healing and has no single point of failure. Ceph is a ideal replacement for legacy storage systems and a powerful storage solution for object and block storage for cloud computing environments.


Ceph Storage


GLUSTER – Red Hat describes Gluster as a scale-out NAS and object store. It uses a hashing algorithm to place data within the storage pool, much as Ceph does. This is the key to scaling in both cases. The hashing algorithm is exported to all the servers, allowing them to figure out where a particular data item should be kept. As a result, data can be replicated easily, and the lack of central metadata files means that there is no bottleneck in accessing, as might occur with Hadoop.
GlusterFS is designed for today’s high-performance, virtualized cloud environments. Unlike traditional data centers, cloud environments require multi-tenancy along with the ability to grow or shrink resources on demand.
GlusterFS is an open source, distributed file system capable of scaling to several petabytes (actually, 72 brontobytes!) and handling thousands of clients. GlusterFS clusters together storage building blocks over Infiniband RDMA or TCP/IP interconnect, aggregating disk and memory resources and managing data in a single global namespace. GlusterFS is based on a stackable user space design and can deliver exceptional performance for diverse workloads.


GlusterFS Architecture



Ceph and Gluster have similar data distribution capabilities. Ceph stripes data across large node-sets, like most object storage software. This aims to prevent bottlenecks in storage accesses.


Because the default block size for Ceph is small (64KB), the data stream fragments into a lot of random IO operations. Disk drives can generally do a maximum number of random IOs per second (typically 150 or less for HDD). Just as important, that number doesn’t change much as the size of the transfer increases, so a larger IO size will move more data in aggregate than a small block size.


Gluster uses a default value of 128KB. The larger default size is the primary reason that Red Hat claims to outperform Ceph by three to one in benchmarking tests. But, Ceph can also change chunk size from 64KB to 256KB or even 1MB, and doing so would probably have given Ceph the performance edge.


Both systems avoid single-node metadata, and so should scale nearly linearly. Data deduplication should not be very different in performance. Compression at the server makes equal sense, too, reducing both storage space used and network traffic and lowering the amount of disk IO needed for each file.