Week 2 File Systems & Unix Commands

File System Hierarchy

File Names & Extensions File Name: used so that the computer can easily remember the date within File Extensions: allow the operating system to know what application opens the file

File Manipulation

What is AFS? AFS (Andrew File System): is a distributed file system which makes it possible for users to access information from any computer on a network Security Kerberos: used to authorize the user to the system ACL (Access Control List): used to grant privileges to users for all directories on the network. Volumes: To help in scalability, AFS uses volumes, a volume keeps a set of related files & directories together on a disk, which allows admins the ability to add and remove without us losing our data

AFS File Tree

Pathnames

Relative Pathnames ~/ : The ~/ references your home directory, this will be used as a shortcut to get us back to our home directories.. : refers to the directory above the current working directory. : refers to the current working directory

Relative pathname practice The path can be expressed../.elm/inbox ~/.elm/inbox./../.elm/inbox

Client/Server Relationship Server: Is a powerful computer dedicated to managing, which sole task is to govern access to information and “serve” information requested by the client. Client: Is a normal computer, or another server, that request the information from the server and relies on information from the server to complete its task Who is the client and who is the server on NCSU network?

SSH Secure Shell: is a program that allows a computer to connect over a network and execute commands on a remote computer It provides a secure and encrypted connection over an insecure network Also protects networks from attacks such as IP spoofing, IP source routing, and DNS spoofing Uses “tunneling” to group information together in secure SSH packets before sending it over a network

Accessing AFS Windows Students Double click putty.exe icon on desktop Click ‘Eos’ then ‘Load’ Mac Students Open ‘Terminal’ Enter ‘ssh –X *replace userID with your UnityID