What is SAN storage?
SAN expandable to storage area network is a high speed independent data transfer interconnected network offering consolidated storage resources to several servers. It moves the storage resources from public network and restructures them into a dedicated high performing network. This facilitates each server to access the shared storage as if it was an attached drive eliminating network bottlenecks.
SAN storage solutions initially came in the form of fiber Channel (FC) which worked out to be quite expensive, complicated and difficult to manage. In recent times these issues have been reduced with the introduction of 10 gigabit Ethernet (10GbE) Internet Small Computer System Interface (ISCSI) that is more affordable and flexible. Both the types are still widely being adopted depending on individual business requirements.
The primary advantage of SAN has been the virtualization of storage. Large pools of consolidated storage are now available for all software applications without the need to check the server capacity of individual storage devices. The second important benefit with SAN is the backup. Snapshots and data replication comes as a protection at times of disasters and with SAN the centralized data backup process is done faster and in a more cost-effective manner. SAN has also eliminated the process of using DAS (direct attached storage) where manual efforts are required to install more storage. SAN also minimizes the downtime and the need to reboot. All the storage needs can be managed from one single console. Another crucial benefit is it ensures failover protection even if one server encounters issues or is down for maintenance traffic is diverted automatically to other servers.
Comparing SAN with NAS
SAN and NAS (Network-Attached Storage) are both network based storage solutions. They exhibit similarities as well as differences at the same time. Both SAN and NAS allow their users to access storage devices remotely. The services they provide creates confusion within the users but the technology diverge at every point of their characteristic. Let’s go through the difference one by one to get a more clear idea-
| NAS | SAN |
| Uses TCP/IP networks, most commonly Ethernet | Runs on high speed fibre channel networks |
| Data processing is done on file-based data | Data processing is done on block-based data |
| Uses several protocols to connect with servers including NFS, SMB/CIFS, etc. | Uses SCSI protocol to communicate with the servers. |
| Has lower throughput and higher latency because of its slower file system layer | A higher performance for environments that need high-speed traffic |
| NAS devices are not highly scalable. Though some high-level NAS systems can be scaled up to petabytes with the use of clusters | SAN is way more scalable than NAS and thus enables admins to scale performance and capacity in configurations |
| Easier to manage and devices can be easily plugged into LAN, thus a simplified management interface | To plugin to SAN requires more administration time and expertise than NAS |
| NAS is generally lies towards the lower price range but some high end NAS are more costly than entry level SAN | SANs are generally costlier and need complex maintenance with FC SANs on top. |
