I am new to storage domain .can Some one please help me in understanding the below things Can a storage sever be connected to Application server?
1.How storage servers are different from applications servers
2.Can multiple application servers connect to storage serves over the network
3.what kind of files will be served by NAS and SAN severs
Firstly this question belongs on server-fault stack exchange still it is a good conceptual question...
So the answers are~~
Yes storage servers can connect to application server (app servers are in fact software frameworks or specific portion of a server program implementation). Application servers communicate with storage server to store / retrieve / process data.
Apart from high disk space, what else is different about storage servers you may ask ? In many cases, they come with a host of specialized services. This can include storage management software, extra hardware for higher resilience, a range of RAID (redundant array of independent disks) configurations and extra network connections to enable more users to be desktops to be connected to it.
Where as, application server is a software program that handles all application operations between users and an organization's backend business applications or databases. An application server is typically used for complex transaction-based applications. To support high-end needs, an application server has to have built-in redundancy, monitor for high-availability, high-performance distributed application services and support for complex database access. For mobile computing, mobile app server is mobile middleware that makes back-end systems accessible to mobile applications to support Mobile application development. Frankly speaking, application servers lie in the territory between database servers and the end user, and they often connect the two.
Multiple application servers CAN and in reality DOES connect to storage serves over the network or even directly. but for concurrent access to data there must be guaranteed reliability of data between transactions. Something like ACID properties.
Cming to the third one, NAS, it turns out, is NOT really storage networking. Actual network-attached storage would be storage attached to a storage-area network (SAN). NAS, on the other hand, is just a specialized server attached to a local-area network. All it does is make its files available to users and applications connected to that NAS box — much the same as a storage server. To further conceptualize the difference between a NAS and a SAN, NAS appears to the client OS (operating system) as a file server (the client can map network drives to shares on that server) whereas a disk available through a SAN still appears to the client OS as a disk, visible in disk and volume management utilities (along with client's local disks), and available to be formatted with a file system and mounted.
