Andrew File System
The Andrew File System (AFS) is a distributed network file system that enables files from any AFS machine across the country to be accessed as easily as files stored locally. It is an enterprise file system designed for use in a distributed environment on multiple computing platforms. AFS allows users on various types of computers to access the same file system. To a casual UNIX user, AFS disk space looks like a regular local disk; to Windows and Mac OS X users, it looks like a normal network drive. So with a single namespace and Kerberos authentication, AFS allows a user to log into any machine participating in the DCI and be presented their files and/or applications. AFS is composed of cells, with each cell representing an independently administered portion of file space. Cells are composed of two types of machines: fileserver and client. Fileservers are machines that typically store and control the files. A client machine accesses the files. Cells connect to form one enormous UNIX file system under the root /afs directory. PSC organizes and maintains the disk space associated with the cell psc.edu. One can access your PSC AFS space from most of PSC's machines, and can also make your directories accessible to users from any
Like any network application, AFS has two components, a client and a server. The client component resides on each machine that wants to use AFS. This client asks the server for files stored in AFS and the server sends the file to the client over the network. The client then presents the file to the user as if it were local to the machine. When the user makes any changes in AFS space, such as creating a new file, saving a file or deleting files, the client sends the information to the server where updates occur. AFS speeds this process up by using disk caching. The AFS client keeps pieces of commonly used files on local disk. When the user asks the AFS client for a file, it checks to see if that file is in the local disk cache. If it is, the client then asks the server if the file it has in disk cache is up-to-date. If the server reports that the file is up to date, the client is able to present the client with the file that is stored in the local disk cache rather than transferring the file from the server. Both AFS and Sprite file systems are distributed file systems so they use some form of caching. A server in a distributed file system can be stateful or stateless. AFS and Sprite FS are both stateful: in AFS servers keep track of the contents of client's caches, and in Sprite, servers keep track of which clients have which files open. AFS is server driven and Sprite FS is client driven. Different DFSes place different req
Some common words found in the essay are:
Sprite FS, PSC AFS, Mac OS, AFS AFS, System AFS, Additionally AFS, Control Lists, AFS Sprite, Mobility AFS, Kerberos AFS, file system, afs client, local disk, file systems, file close, disk cache, file space, client file, processes file, servers track, servers track clients, local disk cache, afs file space, sprite servers track,
Approximate Word count = 968
Approximate Pages = 4 (250 words per page double spaced)
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