光头老蒋 发表于 2011年03月15日 22:40 | Hits: 4232
Tag: 存储技术


Isilon built and delivered the revolutionary OneFS operating system, which combines three layers of traditional storage architectures – the file system, volume manager and RAID – into one unified software layer. This creates a single intelligent, fully symmetrical file system, achieving up to 20GBps of total throughput, which spans all nodes within a cluster.


File striping in the cluster takes place across multiple storage nodes versus the traditional method of striping across individual disks within a volume/RAID array.


OneFS provides each node with knowledge of the entire file system layout and stripes files across nodes within a single cluster. Accessing any independent node gives a user access to all content in one unified namespace, meaning that there are no volumes or shares, no inflexible volume size limits, no downtime for reconfiguration or expansion of storage and no multiple network drives to manage. This fully distributed approach enables the breakthrough technology required to meet the performance, scalability, availability and manageability demands of the next generation data center.

OneFS 会让每一个存储节点知道整个系统的文件分布条带等文件的索引信息(原文为knowledge),访问一个独立的存储节点就等于是访问了一个全局的namespace server,这种全局的信息保证让整个系统没有容量的限制,没有单点的故障,在带宽,扩展性上,可管理性上做的最好。

(让每一个节点,都能有整个系统的信息,意味着每次数据的更新和增加都必须抄送给所有的节点,以保证在每次数据读取时是最新的数据, 那也就是说,如果集群的数量太大时,假设100,每次数据的读写是1,那么整个系统的写操作就是100+1=101次,大量的数据读写浪费在内部的消息通知上,从Isilon本身的技术文章上没有看到类似 gassip协议或者vector clock nwr之类的算法,所有Isilon最大的问题是不能在超大容量下保持很好的性能。

原文链接: http://www.click2earth.com/post/134.html