I always thought SAN was essentially cloud storage in that you have an external pool of storage servers connected to your LAN.
By my understanding, the limitation is that traditionally, servers from different vendors in a SAN required their own specific storage because of different environments (Windows vs. Linux for example)
Does cloud storage specifically refer to being able to virtualize the servers such that it is vendor-agnostic?
In: Technology
A SAN is a particular type of physical storage device (usually a big storage array connected by fiberchannel or iSCSI). SAN is synonymous with block storage, where the storage array delivers raw blocks of data to the attached computers. It can run on a dedicated storage network (fiberchannel), or over an ethernet (iSCSI)
Cloud storage is a way to buy storage, typically implying that you are renting storage from a Cloud Service Provider (like Amazon AWS, with their EBS block storage and S3 object storage). The oay-per-use model can be very good, but if you stop paying… buh-bye, data.
The cloud service provider *might* use a SAN to manage the Terabytes they rent to you, but mostly they use home-built commodity hardware (plain white-box Linux servers with the cheapest drives they can find… zillions of them, using software RAID or erasure coding to make the storage reliable)
Think of it this way: you can own a Honda Accord… that is like an on-premises SAN (though a better analogy might be a BMW because SAN tends to be high performance), or you can call an Uber which might be a Honda Accord (or a Toyota RAV4 or something else)… that is cloud storage.
For completeness, there is a NAS (network attached storage), which uses NFS or CIFS to deliver files (not blocks) over a TCP/IP network. In corporate environments the big vendor for this is Netapp, but you may have one at home if you have a router with attached storage or an Apple time jachine.
Latest Answers