SAN TECHNOLOGY

A comman PC user have storage space known as hardisk which either inside cpu or hot plugable usb hardisk this can be of size in GBs as per requirment of a user and he can add more hardisk as much as motherbord have hd connectors usually it will b maximum 4 hdd u can attach to a normol system. All these things are fine for home pc user and small enterprises.

But what if a large enterprise or business
1. It require large space in TBs (tera bytes) Or PBs (pentabytes).
2. It reqiure centralized control and managment on storage space.
3. High availability of data from storage even in worst conditions.
4. Highly secure storage space.

All these solutions are provided by SAN TECHNOLOGY.

SAN stands for storage area network . As we know that in large business number of servers and number pc users are more and local hardisk of servers and pc do not have enough amount of space. Also it is very difficult for administrator to manage hardisk of each machine. Future expansion of local hardisk is also not sufficent. So now these kind of big industries are using SAN.

SAN TECHNOLOGY:

one centeralized SAN Box is there which will b connected to SAN switch, all the workstations or servers will b connected so SAN box through these switches. volumes and partions to each server will b given from this SAN Box. But its not that easy as it have to meet hardware reqiurment at server or workstation sites that it shuld have 2 HBA cards. All the connections in SAN are fiber channel so that speed from SAN to host is atleast 4Gbps and assigned partition or volume shuld appear as local hardisk to host. now disk mangment and assignment can be done from a centerlized loction very easily by administrator. As far secutity is concern only volume assigned to a perticular host will b visible to it and other host will not b able to access the volume assigned to any other host and how much space is assigned to other host.
Even if any of hardisk is failed in SAN box data will be still available as these volumes are a part of RAID group and also hot spare disk is available in SAN which will invoke if any disk fail in an DAE enclosure.

HARDWARE IN SAN:

In SAN network there is one SAN box which will be having SP (Storage Processors), SPS (Storage Power Supply) and DAE (Disk Array Enclosure). Each DAE will b having 15 Hardisk space u can add maximum 15 HDD in 1 DAE. you can increase the number of DAE as much as ur SAN model supports.
A smallest can have maximum 120 hardisk if it is having 8 DAE and each DAE is filled with 15 HDD. So if Each HDD is of 300GB(minimum size hardisk in SAN) in that SAN box total space is 36000GB or 35TB. Middium SAN solution have 2400 hardisk space and 32 SP and 8 SPS so if each hardisk is 300GB then total space of 720000GB that is 704TB.
Bigger SANs have 9600 HDD space .