NAS and SAN belong to Networking domain. So now lets see what is NAS and SAN and how are they useful in today’s World?
What is NAS and SAN?
Network Attached Storage or NAS and Storage Area Network or SAN are both used to store data. In earlier days only servers used to stored all the data, due to which it would become slow or overloaded and Administrators used to face memory problems.
NAS and SAN are used ONLY to store data. They don’t do any other thing! Data storing and sharing is their only work.
Network Area Storage
Introduction:
NAS are file servers! As mentioned above all NAS does is store data and nothing else. Data is the big important thing today. So a Network Area Storage is 1 unit to store all the data in your infrastructure. Again all it does is store data and nothing else.
Working:
NAS works as a shared drive on a whole network. So if you work in an office you will have one NAS for the office.
To get the data available in NAS, standard FTP protocols are used. The server administrator stores all the data in NAS, and if clients need this data they can use access it when they need. NAS uses either FTP or SMB or CFS file protocols to get the data. Its up to the administrator which protocols he selects.
NAS structure.
Features:
- One of the most important feature of NAS is the operating system is designed to only share files. So no access to internet.
- This is done so that administrators don’t go into internet and unintentionally download some virus/malware, which can and will destroy all the data.
One thing to note about NAS is, since it is only one machine that only stores data, any problem met on this machine will lead to loss of data and jeopardize your infrastructure.
Storage Area Network
Introduction:
SAN is also a File storing device but it is a network of boxes to store data! In SAN you connect or disconnect any number of SAN devices. All the devices store data in one cluster. This is how data is shared in your network with SAN.
Working:
SAN devices live in a cluster. So there are many devices sharing same data. Suppose there are 10 devices of SAN in a cluster. If one SAN device fails, the data will still be in the other 9. If 2 fails, other 8 can still give the same data. If by Satan’s grace 4 devices fail or 5, the clients can still access the remaining devices and read or write inside SAN.
The client however is unaware of which devices are failed or running. For the client it is only one device which is sharing the resources.
You can also map drives into SAN. When you mount any folder on SAN and the client will use it as if it resides in his own machine even though he’s accessing it from the network.
SAN structure.
Features:
- In SAN, if you want to add data just add the device to the cluster. If one fails, other are still there to give the data. Based on your backup or replication policies the other SAN devices will be there to give data to the network.
- If a client wants to save a APK file into SAN, he can install Eclipse, build an apk file and save it on the SAN and work just like he’s working on his local drive.
- SAN is basically a cluster of devices that have data stored in them. So if you try to connect, you connect to outer cluster. Even if 9/10 devices are down in the cluster, you will still get your data from that one running device.
NAS vs SAN
- If NAS fails the data in unavailable till it comes back online. But if SAN fails your data still resides in other devices in the cluster.
- In NAS you can just add new data to the NAS device. In SAN you can add new drives and based on replication policies, that new data will then be available all over SAN.
- In SAN you can easily add or remove devices, which is not possible in NAS.
- For virtualization scenarios SANs are the best options. You can connect the hypervisors to the SAN and run multiple VMs.
- Example: NAS –> FreeNAS, SAN –> SANmp