Chapter 6. Peripheral Devices
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## Chapter 6. Peripheral Devices

## About Peripheral Devices

In work group computing, peripheral devices connected to one workstation or server can be accessible to everyone. The most common peripheral device to be shared is a printer, but other devices, such as optical scanners, and CD-ROM and tape drives, can also be shared. The advantages of making peripheral devices available throughout the work group include the following:

- Maintenance and administration of peripherals such as printers and scanners can be centralized.

- Resources can be more carefully allocated across the work group.

- Services, such as regular backup, can be centralized.

## Setting Up Peripheral Devices

It is often the responsibility of the administrator to set up peripheral devices. The first thing to consider in setting up a device is its location. Some peripherals, such as printers, scanners, and modems, tend to be kept in a central location (often nearest to the administrator) for ease of administration, maintenance, and security. Other devices, such as tape drives and floppy drives, may be located at users' workstations.

In determining the best location for peripheral devices, consider these factors:

- How many work group members will typically use the device?

- How often will they need the device?

- What special maintenance does the device require (for example, replacing toner)?

- Does the device require any special security precautions?

The information that follows deals with the overall tasks and considerations in setting up, using, and maintaining peripheral devices for a work group. For detailed instructions about setting up a particular peripheral device, see the documentation that came with it as well as IRIX Admin: Peripheral Devices.

### Printers

Printers can be connected to individual workstations or to network print server systems. A print server, which is a printer connected to network print server system, can be shared by multiple users (each of which is a print client).

Work groups often use a print server available to all work group members. It is generally useful to locate a print server centrally, in a location accessible to everyone and convenient for the administrator, who may be responsible for general maintenance and administrative tasks such as replacing toner cartridges and maintaining the print server.

Printers may have parallel, serial, or SCSI interfaces. Any printer, regardless of interface or other hardware characteristics, can be a network print server. Likewise, any system on the network can be a network print server system; it does not need to be a dedicated system. In planning your printer deployment strategy, the volume of print jobs you expect in your work group should play a role in choosing the system or systems you want to use as network print server systems, and in whether those systems are dedicated to that use.

The overall steps in deploying a printer are as follows:

1. Choose a location for the printer.

2. Set up the printer itself.

3. Configure the print server on the print server system.

4. Configure the print server on the print clients.

#### Configuring a Network Print Server

Print servers must be configured on the print server system before remote clients can configure them successfully across the network.

To configure a print server for use across a network, you simply make sure that the print server system is able to communicate on the network. Then, as superuser, grant permission to each client that will use the print server. Typically, you grant permission to a print client with this command:

    # addclient client_name

The command for adding permission for all remote workstations to use the print server is:

    # addclient -a

For more information about configuring a network print server, see IRIX Admin: Peripheral Devices.

#### Configuring a Print Client

Configuring a print client so a network print server can be used simply involves adding the network print server to the client's Print Manager. You must know the hostname of the print server in order to do this. It is also helpful to know the printer type (for example, a PostScript® printer, line printer, plotter, and so on).

Any printer that has been added to the Print Manager can be designated as the default printer for the client system. In most cases, you should designate a default printer for each client system in your work group.

For more information about setting up printer connections on a print client, see the Personal System Administration Guide.

### Printer Administration

Administering printing services for a work group generally involves the following tasks:

- Add and remove printers as necessary.

  You can use the Print Manager to add and remove printers from client systems.

- Change default printers.

  When users' printing needs change, or additional printing resources become available on your network, changing the default printer on some or all workstations may be appropriate. You can use the Print Manager to set as default any printer that has been added to client systems.

- Monitor print server status.

  When a print job is sent from a print client to a print server, it can appear to the client that the job is being printed, regardless of its actual status on the print server. To monitor status of a print request on a print server, use the Print Manager, which can detect the true status of a remote print job over the network.

- Cancel print server requests as necessary.

  When it is necessary to cancel a print request, you can use the Print Manager. Note that if the print server is not handling a large number of requests, and the document to be printed is short, the job may be printed before you can cancel it.

### CD-ROM, Floptical, and Floppy Disk Drives

One of the key concepts in work group computing is that devices connected to one system can be accessible to all systems on the network. The administrator's initial role in regard to CD-ROM, floptical, and floppy disk drives is to determine the appropriate allocation of drives. Depending on the needs of your work group, each system may need its own drive(s), or a single, centrally located drive may suffice.

The overall steps for setting up a CD-ROM, floptical, or floppy disk drive are as follows:

1. Install the drive.

   For specific instructions, see the documentation that came with the drive.

2. Mount the filesystem on the drive for use on the local system.

   You can use the DiskManager to mount filesystems automatically.

3. If the filesystem will be used on remote systems, export the filesystem.

   You must have NFS installed to export a filesystem. See the ONC3/NFS Administration Guide for more information on exporting filesystems.

#### CD-ROM Filesystems

CD-ROM filesystems are always read-only. When you are finished using the filesystem, issue the `eject` command. The filesystem is unmounted and the CD-ROM is ejected from the drive. Any user can unmount and eject a CD-ROM with the `eject` command.

#### Floptical and Floppy Disk Filesystems

Many different kinds of floptical and floppy disk drives are supported, including the following:

- 720 Kb, 3.5” floppy

- 1.44 Mb, 3.5” floppy

- 20.1 Mb, floptical

- 360 Kb, 5.25” floppy

- 720 Kb, 5.25” floppyi

- 1.2 Mb, 5.25” floppy

Silicon Graphics systems automatically determine the format of a floppy disk inserted in your drive, and, if it is a DOS or Macintosh® floppy disk, automatically mounts the filesystem on your default mount directory. Once the filesystem is mounted, you can use typical IRIX commands with it.

You can use a floptical or floppy disk drive like a tape drive for IRIX file transfer. You can use the standard tape archive commands to write files to the floppy disk drive if it is in DOS format.

When you place files on a floppy disk, it is a good idea to make a note on the disk label of the format or the exact command used to place the files on the floppy disk. This makes it much easier for you (and others) to retrieve the files from the floppy disk. Also, whenever possible, change directories to the one that contains the file and place the file on the floppy disk using a relative pathname, rather than specifying the absolute pathname.

Also, be aware that using a floppy disk to transfer files to systems made by other manufacturers may mean that the same tools are not available on the receiving system. The `tar`, `cpio`, and `dd` tools are usually available on all UNIX systems.

### Tape Drives

This section covers what you need to know about the tape drives on your workstation or server. The cartridge tape device is used primarily for filesystem backups and data transfer.

For information on backing up data onto tapes, see IRIX Admin: Backup, Security, and Accounting. If you are installing a tape drive, see the installation instructions furnished with the hardware.

Almost all workstations are configured with some sort of tape device for making backup copies of your files. Whether you maintain one system or a network of hundreds of workstations, you will eventually have to use and maintain some form of tape drive.

#### Adding a Tape Drive

To install a tape drive on an IRIX system, follow the hardware installation instructions furnished with your tape drive. Make sure you carefully follow any instructions regarding drive terminators.

If you are adding a tape drive to a system that does not have one, the software configuration is taken care of automatically when the system boots.

## Troubleshooting

This section discusses some troubleshooting tips for problems arising with peripheral devices.

### Troubleshooting Your Printing System

If you send a print request to a printer and you do not receive any output, use the checklist below to find the problem. You can find additional troubleshooting information in the printer manufacturer's hardware manual, and in IRIX Admin: Peripheral Devices

- Is the printer turned on?

  Printers do not always indicate clearly if they are turned on. Make sure the printer is plugged into the power socket and the power switch is on.

- Does the printer have paper?

  Frequently, printers run out of paper when printing in high volume.

- Is there a paper jam?

  Make sure the entire paper pathway is clear of sheets or fragments of paper. Refer to your printer hardware documentation before attempting to put any unusual paper or other media through your printer.

- Is the printer set to the correct baud?

  Be sure the baud rate of the printer matches that of the serial port.

- Is the serial cable attached correctly?

  Often, reseating the serial cable where it connects to the printer restores correct operation.

- Is the correct cable being used?

  The use of the pins in serial cables varies somewhat in different applications. Cables designed for specific hardware may or may not function correctly with different hardware. Check your system Owner's Guide and the documentation supplied with your printer and cable to determine if the cable is correct for your hardware.

- Did you specify the right printer?

  If your system has more than one printer, and you wish to send a job to a printer other than the default, remember to explicitly choose the printer you want to use.

### Troubleshooting Tape Drives

If you have difficulty accessing a tape drive, use the checklist below to find the problem. You can find additional troubleshooting information in the drive manufacturer's hardware manual, and in IRIX Admin: Peripheral Devices.

- If the tape drive is an external unit, does it have power?

  Simply powering it on does not cause it to be seen by the computer. The system must be shut down, power cycled, then rebooted.

- During the boot phase, do you see the access light on the tape drive light up at all?

  If it doesn't flash at all, chances are the operating system is still not seeing the drive.

- Is the SCSI cabling and termination correct?

  If visual inspection shows nothing obvious, try resetting the connectors. Any movement of hardware or cabling must be done with the system powered off.

- Was the tape device's SCSI address changed when other SCSI devices were added to the system?

- Is the tape drive's read/write head clean?

  Follow the manufacturer's guidelines for maintenance and cleaning.

This covers the basic problems that administrators experience regarding missing tape drives. See the following reference pages for more information on the commands used in this section: `mt`, `ls`, `hinv`. For more technical information about tapes, see `mtio`, `tps`, or `xmt` reference pages.

#### Troubleshooting Tape Read Errors

Often there is a quick and simple fix for an error message that is caused by a tape drive malfunction or the tape itself. Both recoverable and unrecoverable errors can be caused by something as basic as a dirty read/write head, a poorly tensioned tape, or a dropout, which is a physically bad spot on the tape. An EOT message can also mean that there is no data on the tape.

The commands below could help you with some basic tape maintenance and performance functions. Using these commands could either prevent future errors from occurring or help you recover from an existing error condition:

- The `hinv` command determines which tape drive type is connected to your system.

- The `mt status` command verifies the status of the tape drive and the media.

- The `mt retension` command ensures that consistent tension is applied to the tape within the cartridge.

- The `mt reset` command resets the tape drive and controller. Use this command only as a last resort; in some instances it may result in loss of data. In the case of SCSI tape drives, `mt reset` resets all SCSI devices, including disk drives.

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Chapter 5. Identifying Your Work Group |  | Chapter 7. Security