Chapter 1. Overview of System Administration

Underlying the applications and tools you use on your workstation is the operating system (a version of the UNIX operating system). IRIX is much more flexible and powerful than traditional personal computer operating systems in these ways:

Along with the advanced capabilities of the IRIX operating system come certain responsibilities for setting up, maintaining, and troubleshooting it. This set of responsibilities is known as system administration. Click a topic below for more information on general system administration tasks:

Choosing an Administrator

You need to decide who will be responsible for keeping the system in good running order and, if the system is connected to a network, who will work in conjunction with the network administrator to access network services.

About User Privileges

Because many people may use the same system, IRIX provides a built-in security scheme where you can grant different people different capabilities for changing the system. There are three levels of capability:

User  

Any person who has a login account on the system. When users log in, they can change only their personal workareas. Users can run the interactive guides from the System Manager window, but guides that change system information are not available unless a user knows the password for the root account or has been assigned specific administrative privileges.

Privileged User 

A person whose login account includes administrative privileges. The Administrator (see below) of the system can assign privileges to users on an individual basis. Depending on what privileges a user has been assigned, that user can use the interactive guides to make changes to the system. For information about using the Privilege Manager to assign privileges, see “Controlling System Administration Privileges” in Chapter 4.

Administrator 

The person who can use the most privileged account, the root account. This person should have a personal login account for daily use. When there are serious system problems to correct or other key administrative tasks to perform, the administrator logs in to the root account to change system information using the interactive guides or using the IRIX shell. The Administrator can change information in the root account (such as the password) and log in to an IRIX shell as root.

In a large, secure, networked environment run by an experienced network administrator, the scheme could work in this manner:

  • The network administrator is the Administrator for every system; this means that the network administrator is the only person who can use the root account and who knows the root password.

  • The Administrator creates a standard personal login account for each person who uses a particular system.

  • Out of all the users, the Administrator selects one person to be responsible for maintaining the system daily; the Administrator adds administrative privileges to this person's account using the Privilege Manager. See “Controlling System Administration Privileges” in Chapter 4 for more information.

In a smaller, less secure environment where each person has one system, the scheme could work in this manner:

  • Each user is completely responsible for maintaining his or her own system. Users typically perform administrative tasks while logged in to their personal accounts. But when a user must use the IRIX shell with administrative privileges, the user logs into the root account.

  • The Administrator adds login accounts for other people who occasionally need to use the system. If one of these users ever needs to perform administrative tasks, the Administrator assigns the appropriate privileges to the user's account. See “Controlling System Administration Privileges” in Chapter 4 for more information.

The System Administrator's Responsibilities

As the Administrator for a system, you are responsible for performing these tasks:

If your system is part of a network, you are also responsible for these tasks:

The Network Administrator's Role

The responsibilities of a network administrator vary greatly from site to site. If you will be using the network, it's important to contact the network administrator to understand all the services that are available to you. In general, the network administrator is responsible for these tasks:

  • Setting up and maintaining the network so connections are reliable and data is transferred as quickly as possible.

  • Creating, maintaining, and periodically distributing a list of all systems and users so that each has a unique identity on the network.

  • Setting up and maintaining network services such as electronic mail and the Network Information Services (NIS).

For more information on network administration, see Chapter 5, “Network and Connectivity”

Performing System Administration Tasks

You have the following options for performing system administration tasks.

  • The System Manager window provides access to the System Administration guides. These interactive guides lead you step-by-step through the various system administration tasks, such as adding a user account. Each guide consists of pages in which you enter information. After you finish filling out the pages, you simply click the OK button and your system completes the task. For more information, see “Using the System Manager's Interactive Guides”.

  • The IRIX shell accepts IRIX commands that you use for administrative tasks not currently covered by the graphical user interface.

This online information describes how to use the interactive System Administration guides to perform most of the administration tasks; in cases where an interactive guide does not exist for a particular task, you must use IRIX commands or edit system files. If you prefer to perform all administrative tasks without using the interactive guides, see the IRIX Admin set of guides (choose “Online Books” from the Help toolchest, and look in the SGI_Admin bookshelf). Regardless of whether you edit system files manually or use the interactive guides, you are changing the same system files.

Overview of the System Manager

The System Manager window on your system provides access to the System Administration interactive guides described throughout this book. It also provides information about your system's hardware and software configuration, and lets you monitor your system's activity. For more information, see “Using the System Manager's Interactive Guides”.

You can also access System Manager windows for other systems on the network. For information, see the Desktop User's Guide .

Using the System Manager's Interactive Guides

To use the interactive system administration guides, follow these steps:

  1. Choose System Manager from the System toolchest.

    The righthand column of the System Manager window displays an overview of the System Manager and each of its categories. The lefthand column displays a table of contents, organized by the various categories of guides.

  2. To view the various guides, select categories in the lefthand column.

    When you click a category, a list of the guides (and managers) in that category appears in the righthand column.

  3. To open an interactive guide, click the title of the guide in the righthand column.

    After a couple of seconds, the first page of the guide appears. This first page describes the guide and tells you how many pages you'll need to fill out to complete it. (Most guides consist of four to ten pages.)

  4. Read the information on the first page to learn about the guide and then click the Next button to continue.

  5. Enter information in the pages as requested, clicking the Next button to go to each subsequent page. If you want to go back to an earlier page, click the Prev button.

    The last page of the guide, usually titled “Confirm your settings,” gives you the opportunity to view all of the settings you made in the previous pages.

  6. If you agree with the settings on the last page, click the OK button to have the system implement them.

    If necessary, you can click Prev to go back and change any of the settings. You also have the opportunity to quit without performing the task by clicking the Cancel button.


    Note: The guides execute commands in /usr/sysadm/privbin.


Overview of the Categories

The System Manager window provides the following categories of guides. You can find descriptions of each category in the System Manager Overview window.

Software 

Includes the Software Manager, which you can use to install software; and the License Manager, which you use to add, remove, and update software licenses on your system.

Hardware and Devices 

Provides guides that let you manage printers, modems, serial devices, hard disk drives, and removable media devices like CD-ROM, floppy, and tape drives.

Security and Access Control 

Provides guides to help you improve system security, manage user accounts, configure the login process, control access to files, share files and directories, share printers and removable media devices, and change users' privileges on the system.

Network and Connectivity 

Includes guides that let you set up network connections on your local network and over phone lines (including ISDN), turn on NIS (Network Information Services), turn on NFS (Network File System), mount remote filesystems, manage host lists, modify network settings, and set up PPP connections.

Files and Data 

Contains guides that allow you to mount and unmount local filesystems, and perform backups of important files and directories on your workstation.

System Performance 

Provides guides to help you improve performance by creating logical and virtual swap space. Lets you monitor and manage the processes running on your system by using the Process Manager. Also gives you access to information about your system, including the System Log and the System Administration Log.

The window also includes “Overview,” discussed earlier, and “About This System,” which lets you view basic information about your system, including the version of operating system running, the amount of main memory available, and so on.

About the Managers

Many of the categories listed above also include Managers. You can use Managers to view information about particular areas of your system, such as printers, serial devices, filesystem, shared resources, and so on. You can also access various guides from within a Manager window. For example, when you open the Serial Device Manager in the Hardware and Devices category, a window appears and provides information about all the serial devices currently connected to your system. The window also includes buttons that, when clicked, open guides that allow you to add or delete serial devices or modems.

Searching in the System Manager

The System Manager search mechanism allows you to search for keywords in Guides, Managers, and other applications available through the System Manager. Enter the keywords in the text field and either press Return or click the search button.

If you choose to search on more than one term, you can search for items that contain at least one of the keywords, or that contain all the keywords.

Checking the Hardware Configuration

You use the “About This System” item in the lefthand column of the System Manager window to check your system's hardware configuration. The “About This System” window displays detailed information about your system, including your workstation's name, model, and serial number, its IP and ethernet addresses, and other details.

Checking Disk Information

You can view information about disks connected to your workstation using the Disk Manager. Choose System Manager from the System toolchest, select the Hardware and Devices category, and then click “Disk Manager.” A window appears and displays information about the disks currently mounted on your system. For more detailed information about a disk, select it in the window and click the Get Info button.

Checking Removable Media Device Information

To find out information about removable media devices on your system, such as tape, CD-ROM, floppy, floptical, or SyQuest drives, use the Removable Media Manager, also available in the Hardware and Devices category in the System Manager. To view information about a specific device, select it in the Removable Media Manager window, and click the Get Info button. You can also select the icon for the device on your desktop and choose “Get Info” from the Selected toolchest.

About SCSI Devices, Controllers, and Addresses

You can connect several Small Computer System Interface (SCSI) devices, such as hard disks, tape drives, floppy drives, and printers, to your system. Your system has at least one SCSI controller (an internal board that sends data to and from the devices). The SCSI controller to which your system disk is connected has an ID number of 0. Each SCSI controller can support up to seven devices.

The instructions that come with each SCSI device show you how to physically set its address; your system's owner's guide shows you how to connect the device to the SCSI port, and how to daisy-chain several SCSI devices together.

To check the available SCSI addresses, click “SCSI” in the “About This System” window. (To open the window, choose System Manager from the System toolchest and click “About This System.”) You can find out the type, controller, and address of each SCSI device that is connected to the system.

Using the Shell Window

To perform administrative tasks that are not supported by the interactive guides, use the root account in a shell window. The home directory for the root account is the root (/) directory of the filesystem. The user logged in to the root account can move, change, and delete every file and directory on the system, regardless of who owns them and what type of permissions they have set. Be sure to create a password for the root account that only you, as the Administrator, know. (See “Controlling System Security” in Chapter 4.)


Note: Some UNIX and IRIX documents refer to the user of the root account as the superuser.

When you're already logged in as a regular user, you can start a shell window and log in as root by following these steps:

  1. Choose “Open Unix Shell” from the Desktop toolchest.

  2. Position your cursor within the new window and type

    login root

    Then press Enter.

    If a prompt for a password appears, type the password, then press Enter. If a prompt appears but the root account has no password, just press Enter. (See “Modify Any Account Password” in Chapter 4 to create, change, or remove a password.)

You are now logged in to the root account and are located in the root (/) directory. When you are logged in as root, the IRIX prompt is a pound sign (#) rather than a percent sign (%).

To log out of the root account, type

logout

Then press Enter. The shell window disappears.

Setting the Time and Date

Once you set the date and time, the system can accurately stamp the time of events, such as when you last changed a file. On most networks, the current date and time are periodically provided to all workstations on the network.

You set the date and time by using the IRIX date command in either of the following formats:

date [mmddhhmm[yy]]

date [mmddhhmm[yyyy]]

mm specifies the month, dd the day, hh the hour, and mm the minutes. You can also specify the last two digits of the year (yy) or all four digits of the year(yyyy). For more information and options, see the date(1) reference (man) page.

To set the date and time, follow these steps:

  1. Log in as root through a shell window.

    • Choose “Open Unix Shell” from the Desktop toolchest.

    • Position your cursor within the new window and type

      login root

      Then press Enter.

      If a prompt for a password appears, type the password and press Enter. If a prompt appears but the root account has no password, just press Enter.

  2. Check the current time and date of the system by typing

    date

    Then press Enter.

  3. Specify the date and time. For example, if today is March 17 (0317) at 2:30 p.m. (1430) in the year 1992 (92), type

    date 0317143092

    Then press Enter.

  4. To check the date and time, type

    date

    Then press Enter. You see a line similar to this:

    Tue Mar 17 14:30 1992

  5. Log out of the root account by typing

    logout

    Then press Enter. The shell window disappears.

Setting Up Your System

This section describes the how to use System Setup, an online, interactive guide. After you complete System Setup, your system will have the basic information it needs to create a personal workarea for you and to let you communicate with other systems and people on your network.

System Setup takes you through a number of steps such as improving your system's security, putting your system on an existing network, creating a user account for yourself, customizing your desktop, and setting up your connection to the World Wide Web. To run System Setup, follow the steps below.


Note: If you plan to connect your system to an existing network, contact your network administrator for a login name for yourself, a hostname and IP address for your system. If your network runs NIS, also request your NIS domain name.


  1. Log in to the EZSetup account.

    When you turn on your workstation, the login window appears after the system finishes starting up. Use the left mouse button to double-click the EZsetup icon; this launches System Setup.

  2. Make your system secure.

    You can improve your system's security by helping to prevent access to your system by unauthorized users. Step 1 lets you open the “Improve System Security” guide. For more information, see “Controlling System Security” in Chapter 4.

  3. Set up your network connection.

    If your system is already physically connected to a network, you need to configure networking on your system. Step 2 lets you open the “Set Up and Start Networking” guide. For more information, see “Setting Up an Ethernet Connection” in Chapter 5.

  4. Create a user login account for yourself.

    Step 3 lets you open the “Add a User Account” guide. For more information, see “Add a User Account” in Chapter 4.

  5. Customize your work environment.

    Step 4 provides two sets of steps that let you set up your connection to the World Wide Web and customize your user environment on the system.

    After you complete the last step, click the Quit System Setup button. A notifier may appear concerning JavaScript; click OK to restart the system.

    The “Restart the System” guide appears; follow the instructions in the guide. After the system restarts, you see the login window.

  6. If you want to perform additional administration tasks, go to “Performing Other Administration Tasks” for more information. (You may need to log into the root account to perform the tasks; see “Logging In to and Out of Your System” for information.)

  7. If you want to log in to your new user account now, follow the instructions in “Logging In to and Out of Your System”.

Performing Other Administration Tasks

After you've set up your basic system, you may want to perform one or more of the following administration tasks using the interactive System Administration guides. The guides are available in the System Manager; to open the System Manager, choose “System Manager” from the System toolchest. For more information, see “Using the System Manager's Interactive Guides”.


Note: You need root privileges to perform most of these tasks. This means that you are logged into the root account, you know the root password, or you have been given the necessary privileges by the administrator (root user) of the system.


Logging In to and Out of Your System

You need to log in to the root account to perform most system administration tasks.

Logging In to Your System

To log in to your personal workarea on the system, follow these steps:

  1. In the login window, find the icon that is labeled with your login name and double-click it; if your account has no password, the system logs you in.

    If an icon for your account doesn't appear in the login window, type your login name in the field and press Enter.

  2. If a Password field appears, enter the password, then click the Login button.

To add new user accounts on the system, see “Add a User Account” in Chapter 4.

Logging Out of the System

You can log out of the system to end your current login session. Make sure you save all your work before you log out.

To log out of the system, follow these steps:

  1. Choose Log Out from the Desktop toolchest.

    A notifier appears and asks if you want to log out now.

  2. Click Yes to log out now or click No if you want to continue your login session.

Shutting Down or Restarting the System

Use the methods described here to shut down or restart your system; simply powering off your system may cause you to lose data.

Shutting Down the System

When you shut down the system, the IRIX operating system closes down all processes and files in a specific order so that no information is lost. You should always close your own files and stop running applications before you shut down the system.

To shut down the system, follow these steps:

  1. Choose “System Shutdown” from the System toolchest.

  2. The “System Shutdown” guide appears with several options available, depending on the type of workstation you have.

    • If your workstation does not have the ability to automatically power off, no options appear in the notifier; click the OK button to continue the shutdown, then turn off the workstation when you see the message that says the workstation is ready to be powered off.

    • If your workstation can power off automatically, you can choose to have it do so, and choose to have it automatically power on at a certain time. After you set the options, click the OK button continue the shutdown.

Restarting the System

When you restart the system, the IRIX operating system closes down all processes and files in a specific order so that no information is lost, then it restarts the system.

You should always close your own files and stop running applications before you restart the system.

To restart the system, choose “Restart System” from the System toolchest.