To Back Up Your System

This section provides instructions for backing up your system, including how to back up the root volume group, verify a backup tape, and back up a user volume group.

Complete the Prerequisites

• All hardware must already be installed, including external devices, such as tape and CD-ROM drives.
• The bos.sysmgt.sysbr fileset in the BOS System Management Tools and Applications software package must be installed. The bos.sysmgt.sysbr fileset is automatically installed in AIX Version 4.3. Enter the following command to determine if the bos.sysmgt.sysbr fileset is installed on your system:

  lslpp -l bos.sysmgt.sysbr

  If your system has the bos.sysmgt.sysbr fileset installed, continue with either "To Back Up the Root Volume Group" or "To Back Up a User Volume Group"

  If the lslpp command does not list the bos.sysmgt.sysbr fileset, install it before continuing with the backup procedure. Refer to "To Install Software and Service Updates with Custom Install" for instructions, or enter the following command:

  installp -agqXd device bos.sysmgt.sysbr

  where device is the location of the software; for example, /dev/rmt0 for tape drive.

To Back Up the Root Volume Group

Use either Web-based System Manager or SMIT to create a system backup, stored either on a tape or in a file. To boot from a system backup, the backup image must be stored on a tape.

Using Web-based System Manager

To use the Web-based System Manager application to back up the root volume group, enter the fast path, as follows:

  wsm backup

Using SMIT

1. Log in as root user.
2. Mount all file systems you want to back up. Refer to the mount command for details.

   Note: The mksysb command does not back up file systems mounted across an NFS network.

3. Unmount any local directories that are mounted over another local directory.
4. Make at least 8.8MB of free disk space available in the /tmp directory. The mksysb command requires this working space for the duration of the backup.

   Use the df command, which reports in units of 512-byte blocks, to determine the free space in the /tmp directory. Use the chfs command to change the size of the file system, if necessary.

   For example, the following command adds 12MB of disk space to the /tmp directory of a system with 4MB partitions:

   chfs -a size=+24000 /tmp

5. Enter the smit mksysb fast path.

   The Back Up the System appears, highlighting the Backup DEVICE or File field.

6. Decide which medium you will use to store the backup and select the Back Up DEVICE or FILE field. If you want to create a bootable backup, the medium must be tape. Depending on the medium you chose, follow the appropriate step below:

   TAPE	Press the F4 key to list available tape devices and highlight the device name.
   FILE	Enter a full path and file name in the entry field.

7. If you want to create map files, select the Create Map Files? field and press the Tab key once to change the default value to yes.

   Map files match the physical partitions on a drive to its logical partitions. When installing from a backup image, the BOS installation program uses map files to position the logical volumes on the target drive in the same partitions they were on in the source system. If you do not create map files, the installation program relies on the Logical Volume Manager (LVM) to determine placement for the logical volumes. For more information, see "Using Map Files for Precise Allocation" in AIX Version 4.3 System Management Guide: Operating System and Devices .

8. If you want to exclude certain files from the backup, create the /etc/exclude.rootvg file, with an ASCII editor, and enter the patterns of file names that you do not want included in your system backup image. The patterns in this file are input to the pattern matching conventions of the grep command to determine which files will be excluded from the backup. If you want to exclude files listed in the /etc/exclude.rootvg file, select the Exclude Files field and press the Tab key once to change the default value to yes.

   For example, to exclude all the contents of the directory called scratch , edit the exclude file to read as follows:

   /scratch/

9. If you want each file listed as it is backed up, press the Tab key once to change the default value of List files as they are backed up? to yes. Otherwise, you will see a percentage-completed progress message while the backup is created.
10. The image.data file contains information about the sizes of all the file systems and logical volumes in your rootvg. If you modified the image.data file and don't want a new file created, press the Tab key once to set the value to no for Generate new /image.data file?.
11. If you chose to create a bootable tape and you want to expand the system's /tmp file system (if required by the backup program), press the Tab key once to change the value for EXPAND /tmp if needed? to yes.
12. If the tape drive you are using provides packing (or compression), set the Disable software packing of backup? field to yes.
13. If you chose tape as the backup medium, select the Number of BLOCKS to write in a single output field and enter the number of blocks to write for the tape device used to create the backup image, or leave the field blank to accept the system default.
14. If you chose file as the backup medium, press the Enter key. If you chose tape as the backup medium, insert the first blank backup tape into the drive and press the Enter key.
15. The COMMAND STATUS screen appears, showing status messages while the system makes the backup image.

    If you chose tape as the backup medium, the system may prompt you to insert the next tape during the backup by displaying a message similar to the following:

    Mount next Volume on /dev/rmt0 and type return.

    If this message appears, remove the tape and label it, including the BOS version number. Then insert another tape and press Enter.

    When the backup process finishes, the COMMAND: field changes to OK.

16. Press F10 to exit SMIT when the backup completes.
17. If you chose tape as the backup medium, remove the last tape and label it. Write-protect the backup tapes.
18. Record any backed up root and user passwords. Remember, these passwords will be active if you use the backup to either restore this system or install another system.

You have created the backup of your root volume group (rootvg). If you created bootable tapes, these tapes can be used to start your system if for some reason you cannot boot from hard disks.

To Verify a Backup Tape

Use either Web-based System Manager or SMIT to list the contents of a mksysb backup tape. The contents list verifies most of the information on the tape, but does not verify that the tape can be booted for installations. The only way to verify that the boot image on a mksysb tape functions properly is by booting from the tape.

Using Web-based System Manager

To use the Web-based System Manager application to verify a backup tape, enter the fast path, as follows:

  wsm backup

Using SMIT

Enter the smit lsmksysb fast path. The List Files in a System Image screen appears.

Note: Do not press the Enter key until you finish providing values in the entry fields.

To Back Up a User Volume Group

Use either Web-based System Manager or SMIT to back up user volume groups, to images different than root volume group images.

Using Web-based System Manager

To use the Web-based System Manager application to back up a user volume group, enter the fast path, as follows:

  wsm lvm

Using SMIT

Back up a user volume group by entering the smit savevg fast path. The Save a Volume Group screen appears.

Use the steps for backing up the root volume group as a guide for backing up user volume groups, with the following exception: If you want to exclude files in a user volume group from the backup image, create a file named /etc/exclude.volume_group_name, where volume_group_name is the name of the volume group you want to backup. Then edit /etc/exclude.volume_group_name and enter the patterns of file names that you do not want included in your backup image. The patterns in this file are input to the pattern matching conventions of the grep command to determine which files will be excluded from the backup.