What is SAN or Storage Area Network

Data has been growing at a rapid pace and storage technology is also growing at a rapid pace to meet requirements and drive innovation. When the term storage is referred to, it is not just confined to storage capacity, there are other requirements as well – requirements like data protection, speed of access to data etc. also go along.

There are 3 types of storage technologies – DAS, NAS and SAN. DAS stands for Direct Attached Storage – Storage is directly to attached to your computer or server. NAS stands for Network Attached Storage – Network is a LAN or Ethernet network, which is very common office network.

SAN stands for Storage Area Network. It has terminologies similar to a LAN/WAN network and is not something which PeopleSoft Administrators will directly deal with but the likely chances of working with a SAN server are highly likely due to increasing popularity of SAN servers.

SAN or Storage Area Network is a specialized high speed, high availability network that uses fiber channel technology to connect servers to storage disks. SAN does not necessarily eliminate the traditional way of doing things. It is connected within an existing network and provides better way of doing several operations like backups etc.

Components that make up SAN:

1. Host – You can have any host be it Windows, Linux or Unix sever or a mix of those.
2. Host Bus Adaptor – Similar to an ethernet card. It generally has 2 ports. If you have a card with one port, you use two cards. It is to create redundancy in your network and remove down-time.
3. Fiber Channel Cable – Similar to ethernet cable.
4. Fiber Channel Switches – Similar to routers to access storage
5. Multi-Pathing Software – Example EMC PowerPath Software
6. Storage Arrays – Several (even hundreds of) storage disks combined together.

Benefits of SAN:

1. Storage area can be accessed by multiple servers simultaneously.
2. Storage resources can be centrally managed and storage space can easily be allocated or deallocated to hosts.
3. Components are hot-swappable, which eliminates the need for down-time.
4. Eliminates the amount of data that can be accessed by a server as opposed to server with directly attached disks.

Common terms associated with SAN:

1. Fabric – Encompasses all hardware that connects servers and workstations to storage devices through the use of fiber channel switching technology.
2. Fiber Channel – It is a high speed network technology used for storage.
3. Node – Any device connected to SAN.
4. WWN – World Wide Name. It is a unique identifier for storage device identification.