Hardware Reference
In-Depth Information
FIGURE 11.1: Notional diagram of OneFS distributed system. OneFS com-
bines file system, volume manager, and RAID protection into one single in-
telligent, distributed system.
This is the core innovation that directly enables enterprises to success-
fully utilize the scale-out NAS in their environments today. It adheres to the
key principles of scale-out; intelligent software, commodity hardware, and dis-
tributed architecture. OneFS is not only the operating system but also the
underlying file system that drives and stores data in the Isilon scale-out NAS
cluster.
11.2.1 Isilon Node
OneFS works exclusively with the Isilon scale-out NAS nodes, referred to as
a \cluster." A single Isilon cluster consists of multiple \nodes," which are con-
structed as rack-mountable enterprise appliances containing: memory, CPU,
networking, non-volatile random-access memory (NVRAM), low-latency In-
finiband interconnects, disk controllers, and storage media. Each node in the
distributed cluster thus has compute or processing capabilities, as well as
storage or capacity capabilities.
An Isilon cluster starts with as few as three nodes and can scale to 144
nodes. There are many different types of nodes, all of which can be incor-
porated into a single cluster where different nodes provide different ratios of
capacity to throughput or I/O operations per second (IOPS).
OneFS has no built-in limitation in terms of the number of nodes that
can be included in a single system. Each node added to a cluster increases
aggregate disk, cache, CPU, and network capacity. OneFS leverages each of
the hardware building blocks, so that the whole becomes greater than the
sum of the parts. The RAM is grouped together into a single coherent cache,
allowing I/O on any part of the cluster to benefit from data cached anywhere.
NVRAM is grouped together to allow for high-throughput writes that are safe
across power failures. Spindles and CPU are combined to increase throughput,
capacity, and IOPS as the cluster grows, for access to one file or for multiple
les. A cluster's storage capacity can range from a minimum of 18 TB to a
