Local Network Data Storage
Decided to write a small article on data storage networks (CDDs), the topic was quite interesting, but in Habré it was somehow not solved. I'll try to share personal experiences in building and supporting SAN.
What is it?
Data storage networkor Storage Area Network is a system consisting of data storage devices, disk, or RAID, a set of deposits, tape libraries and other forms of data transmission and servers connected to it. Usually, large companies with advanced IT infrastructure are used to secure data storage and fast access.
Simplifiedly, the CCB is a system that allows the servers to be given reliable fast disks of variable capacity from different data storage devices.
A little theory.
The server to the data warehouse can be connected in several ways.
The first and most simple - DAS, Direct Attached Storage (direct connection), without stacking disks into the server, or a set in the server adapter, and receives many hygabytes of disk space with relatively rapid access, and with the use of RAID-Massiv, sufficient reliability, although copies of reliability have been broken for a long time.
However, this use of disk space is not optimal, one server is running out, and there is still a lot on the other. The solution to this problem is NAS, Network Attached Storage. However, with all the advantages of this decision, flexibility and centralized management, there is one significant disadvantage - the speed of access, and the network of 10 hygabits has not yet been implemented in all organizations. And we're approaching the data storage network.
The main difference between SAN from NAS (in addition to the lettering in the abbreviations) is how the connecting resources are seen on the server. If NAS resources are connected to NFS or SMB protocols, in SAN we get access to a disk with which we can work at the level of the Block Start Operations, which is much faster than the network connection (plus the large-casm controller adds speed to many operations).
