NAS And SAN: What’s The Difference?
What’s in an acronym? As far as network data sharing and the deployment of storage hardware are concerned, there’s quite a bit of difference between NAS and SAN. And as we’ll see, there are greater opportunities for cost saving and IT flexibility with one form of shared storage, than with the other.
What Is NAS?
Network attached storage or NAS is a dedicated server or appliance, used for file storage and sharing. In addition to the capabilities of traditional file serving and direct attached storage, NAS provides advanced functionality in terms of data storage, access, and management.
NAS systems are networked appliances including one or more storage drives, which are often arranged in logical, redundant storage containers or a RAID (redundant array of inexpensive disks) configuration.
Network attached storage assumes the responsibility for file serving on the network, freeing up other servers. NAS provides access to files using network file sharing protocols such as NFS (network file system), SMB (server message block), or AFP (Apple file protocol). It’s designed for heavy network systems, which may be processing millions of transactions per minute.
What Is SAN?
A storage area network or SAN is a dedicated high-speed network or sub-network providing access to block-level storage, by interconnecting and presenting shared pools of storage devices to multiple servers. The consolidated block level storage array of a SAN can interconnect storage devices, switches, and hosts. High-end enterprise SANs may also include SAN directors, for high performance and more efficient capacity utilization.
Servers primarily identify a SAN as local attached storage, so multiple servers can share a common storage pool. Since SANs are not dependent on the local area network or LAN, they relieve pressure on the local network by offloading data directly from attached servers.
Segregating storage traffic from the rest of the LAN improves application availability and performance. And with a pool of storage capacity available across a range of different workloads, SANs enable enterprises to more easily allocate and manage their storage resources, achieving better efficiency.
How Do They Compare?
NAS uses TCP / IP networks (commonly known as Ethernet), while SANs typically run on high-speed fiber channel networks. Flash-based fabric protocols are helping to close the gap between fiber speeds and slower IP, allowing SAN systems to maintain a high performance.
The network architecture of a SAN is particularly suitable for systems administrators looking to scale performance and capacity. By contrast, most NAS devices are not scalable. Moreover, NAS typically costs more than SAN, and is generally difficult to purchase and maintain.
SAN systems based on hardware have a reputation for being more complex to manage – but this can now be offset through the use of virtualization.
The Value Of Virtualized Storage
Through the software-based control of processes and connections which were formerly considered hardware resources, virtualization allows traditional IT models to be shifted away from legacy proprietary hardware to virtualized environments where software and application migration are possible.
A virtual SAN is a logical or virtual partition, located inside a storage area network (SAN). Network traffic can be segregated within a certain range of the storage area network, so if a problem occurs within a particular partition, it can be dealt with in isolation. Virtualized storage and execution environments allow troubleshooting and testing operations to be performed, without having a negative impact on the rest of the network.
StarWind VSAN delivers performance and reliability using commercial off-the-shelf hardware, removing the need for costly proprietary components. And StarWind Virtual SAN eliminates the need for physical shared storage by mirroring internal hard disks and flash between hypervisor servers. It maintains high performance and high data availability on minimal resources.
For those who need to build and maintain virtualization infrastructure at little to no expense, StarWind Virtual SAN Free offers a no-cost alternative.