Configuring Tape Coordinator Machines and Tape Devices
| Chapter 6. Configuring the AFS Backup System |

## Configuring Tape Coordinator Machines and Tape Devices

This section explains how to configure a machine as a Tape Coordinator machine, and how to configure or remove the Tape Coordinator associated with a single tape device or backup data file.

### Note

When configuring a tape device attached to an AIX system, you must set the device's tape block size to 0 (zero) to indicate variable block size. If you do not, it is possible that devices attached to machines of other system types cannot read the tapes made on the AIX system. Use the AIX smit program to verify or change the value of the tape block size for a tape device, as instructed in Sep 3.

### To configure a Tape Coordinator machine

1. Verify that you are authenticated as a user listed in the /usr/afs/etc/UserList file. If necessary, issue the bos listusers command, which is fully described in To display the users in the UserList file.

          % bos listusers <machine name>

2. Become the local superuser root on the machine, if you are not already, by issuing the su command.

          % su root
          Password: <root_password>

3. Install one or more tape devices on the Tape Coordinator machine according to the manufacturer's instructions. The Backup System can track a maximum of 58,511 tape devices or backup data files per cell.

   If the Tape Coordinator machine is an AIX system, issue the following command to change the tape device's tape block size to 0 (zero), which indicates variable block size. Repeat for each tape device.

          # chdev -l 'device_name' -a block_size='0'

   where device_name is the tape device's device name (for example, /dev/rmt0h).

4. Verify that the binary files for the backup, butc, and fms commands are available on the local disk. If the machine is an AFS client, the conventional location is the /usr/afsws/etc directory.

          # ls /usr/afsws/etc

5. Create the /usr/afs directory. (If the Tape Coordinator machine is also configured as a file server machine, this directory already exists.) Then create the /usr/afs/backup directory.

          # mkdir /usr/afs
          # mkdir /usr/afs/backup

6. Use a text editor to create the /usr/afs/backup/tapeconfig file. Include a single line for each tape device or backup data file, specifying the following information in the indicated order. For syntax details and suggestions on the values to use in each field, see Configuring the tapeconfig File.

   - The capacity of tapes to be used in the device, or the size of the backup data file

   - The device's filemark size

   - The device's device name, starting with the string /dev/

   - The device's port offset number

7. Decide which user and group are to own the /usr/afs/backup directory and /usr/afs/backup/tapeconfig file, based on the suggestions in Granting Administrative Privilege to Backup Operators. Correct the UNIX mode bits on the directory and file, if necessary.

          # chown admin_owner /usr/afs/backup
          # chown admin_owner /usr/afs/backup/tapeconfig
          # chgrp admin_group /usr/afs/backup
          # chgrp admin_group /usr/afs/backup/tapeconfig
          # chmod 774 /usr/afs/backup
          # chmod 664 /usr/afs/backup/tapeconfig

8. Issue the backup addhost command to create a Tape Coordinator entry in the Backup Database. Repeat the command for each Tape Coordinator.

          # backup addhost <tape machine name> [<TC port offset>]

   where

   addh

     Is the shortest acceptable abbreviation of addhost.

   tape machine name

     Specifies the Tape Coordinator machine's fully qualified hostname.

   TC port offset

     Specifies the tape device's port offset number. Provide the same value as you specified for the device in the tapeconfig file. You must provide this argument unless the default value of 0 (zero) is appropriate.

### To configure an additional Tape Coordinator on an existing Tape Coordinator machine

1. Verify that you are authenticated as a user listed in the /usr/afs/etc/UserList file. If necessary, issue the bos listusers command, which is fully described in To display the users in the UserList file.

          % bos listusers <machine name>

2. Become the local superuser root on the machine, if you are not already, by issuing the su command.

          % su root
          Password: <root_password>

3. Install the tape device on the Tape Coordinator machine according to the manufacturer's instructions.

   If the Tape Coordinator machine is an AIX system, issue the following command to change the tape device's tape block size to 0 (zero), which indicates variable block size.

          # chdev -l 'device_name' -a block_size='0'

4. Choose the port offset number to assign to the tape device. If necessary, use the backup listhosts command to display the port offset numbers that are already used; for a discussion of the output, see To display the list of configured Tape Coordinators.

          # backup listhosts

   where listh is the shortest acceptable abbreviation of listhosts.

5. Use a text editor to add one or more entries for the device to the /usr/afs/backup/tapeconfig file. Specify the following information in the indicated order. For syntax details and suggestions on the values to use in each field, see Configuring the tapeconfig File.

   - The capacity of tapes to be used in the device, or the size of the backup data file

   - The device's filemark size

   - The device's device name, starting with the string /dev/

   - The device's port offset number

6. Issue the backup addhost command to create an entry in the Backup Database for the Tape Coordinator. For complete syntax, see Step 8 in To configure a Tape Coordinator machine.

          # backup addhost <tape machine name> [<TC port offset>]

### To unconfigure a Tape Coordinator

1. Verify that you are authenticated as a user listed in the /usr/afs/etc/UserList file. If necessary, issue the bos listusers command, which is fully described in To display the users in the UserList file.

          % bos listusers <machine name>

2. Using a text editor, remove each of the Tape Coordinator's entries from the /usr/afs/backup/tapeconfig file.

3. Issue the backup delhost command to delete the Tape Coordinator's Backup Database entry.

          % backup delhost <tape machine name> [<TC port offset>]

   where

   delh

     Is the shortest acceptable abbreviation of delhost.

   tape machine name

     Is the complete Internet host name of the Tape Coordinator machine.

   TC port offset

     Is the same port offset number removed from the tapeconfig file. You must provide this argument unless the default value of 0 (zero) is appropriate.

### To display the list of configured Tape Coordinators

1. Issue the backup listhosts command to list the Tape Coordinators and port offset numbers currently configured in the Backup Database.

          % backup listhosts

   where

   listh

     Is the shortest acceptable abbreviation of listhosts.

The output lists each Tape Coordinator machine and the port offset numbers currently allocated to it in the Backup Database. The appearance of a port offset number does not imply that the associated Tape Coordinator is actually running. Machine names appear in the format in which they were specified with the backup addhost command.

The following example output lists the Tape Coordinators currently defined in the Backup Database of the Example Corporation cell:

       % backup listhosts
       Tape hosts:
           Host backup1.example.com, port offset 0
           Host backup1.example.com, port offset 2
           Host backup2.example.com, port offset 1
           Host backup2.example.com, port offset 3

Granting Administrative Privilege to Backup Operators |  | Defining and Displaying Volume Sets and Volume Entries