File server

File servers manage a work group's applications and data files, so in which they may be shared through the group. File servers are much Input and Output oriented. They pull huge amounts of data off their storage subsystems and pass the data over the network. When data is requested from the file, a file server transmits all records of a file and the whole index to the client.  A client either selects records( based on query criteria) as they are received or loads the overall file and its index  into  memory  and  then  reviews  it. File servers needs several slots for network connections and a huge capacity and fast hard disk subsystem.

File locking is handled through locking the entire file or through locking byre ranges.   There is no separation among write locks and read locks at this level.  When multiple users access the shared files the file server engine checks for contention if it detects contention at the file lock level it waits until the resource is free.

There can be no scheduling multiple users, no lock manager, no cache management, and minimal concurrency control in the Data base management system sense since there is no single engine to that all the needed information is available. These DBMS like features are generally handled through the client software that anticipates the best way to process the data.  Unless every data file is locked for exclusive use and some client side indexing methods is used, whole data must be moved across the network before sort, filtering, or merge operating can be applied. This condition forces heavy network traffic.

Two methods used to minimize the amount of data which passes over the network are: Organizing data so in which the data required through a particular application request    is stored in a single contiguous block.Storing copies of data accessed through more than one user to help with concurrency problems.Certainly, these methods need developers to synchronization handling and build integrity into the processing of the application.