SAN stands for Storage Area Network. Basically SAN store data for your infrastructure.
SAN storage is a robust dedicated special high-speed network specifically for data storage and this network consists of multiple disk arrays, switches and servers. We can call SAN Storage as block level storage. Simply saying SAN is a network of boxes which stores data.
Servers access data from the dedicated and specific parts of the SAN storage. So this is called dedicated access and technically called as Logical Unit Numbers(LUN), this is how the SAN storage gets divvied up. We can assume it as virtual hard disk.
Characteristics of SAN storage
- Simpler to move storage around.
- Combination of hard drives are present
- Server access the storage on SAN as a natural drive on the system.
For example in the form of-> “D:/” or “E:/” etc
When you start using a storage area network what happens is you connect numerous different SAN devices and all of them store your data generally in something like a cluster. SAN storage stores and provides access to large amounts of data.
You can create a cluster of these storage devices and if anyone fails all of your data is still there. It is still accessible depending on what the replication strategy and the redundancy are provided. you can have entire boxes completely and utterly fail but the data will still be there which still be able to write and send to you.
The other important thing with the SAN in storage is you can actually mount drives to the SAN and have that folder on the SAN, seem as if it is a local hard drive to your computer by using fibre channel or using something called I scuzzy. Why this is important because you can install software from sitting at your computer and you mount to the SAN in storage. This would seem as if it is running locally anything that you would want to do local. Now you could store it on the SAN and not worry about losing that data that becomes very very important especially when we start dealing with virtualization.
The best part is you can add storage to SAN. The other reason that sands are becoming so important is because of virtualization- Instead of having 50 Hardware boxes i.e., 50 physical servers sitting in our data center we now have 5 or 6 physical servers with 50 instances of server operating systems with a flow in between all of those physical servers.
When a server accesses the data on a SAN, it accesses the data as if it was a local hard drive because that’s how operating systems recognize a SAN. SAN storage area network recognized as a local attached hard drive rather than a shared network drive like in a NAS.
SANs are also highly scalable because adding more storage space can easily be done without an interruption on the
SAN storage area network containing all of the devices are connected to each other and they are interconnected using fiber channel which is a standard for SANs.
As Fiber channel is fiber optics and it has speeds between 2 gigabits per second all the way up to 128 gigabytes per second. So fiber channel is extremely fast and it’s also very expensive and most SANs today use fiber channel. But also as an alternative to fiber channel some SANs use iSCSI instead Which is a cheaper alternative to fiber channel, but it’s also not as fast as fiber channel.
The main reasons for using a SAN in storage is because SANs are not affected by network traffic. Such as bottlenecks that can happen in a local area network and this is because SANs aren’t really a part of a local area network. SANs are partitioned off. It’s basically a network all by itself and other reasons for SANs as it is mentioned before SANs are highly scalable and they are also very redundant.
Disadvantage of SAN
SANs are not cheap. They come at a very high cost which is why they are mainly used by large companies and large
organizations. It Required specialized skills to maintain the SAN storage.