Preparing to create system backups

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Meet these prerequisites before creating system backups.

Before creating system backups, complete the following prerequisites:
  • Be sure you are logged in as root user.
  • Consider altering passwords and network addresses if you use a backup to make master copies of a source system. Copying passwords from the source to a target system can create security problems. Also, if network addresses are copied to a target system, duplicate addresses can disrupt network communications.
  • Mount all file systems you want to back up. The mksysb command backs up mounted JFS (journaled file systems) and JFS2 (enhanced journaled file systems) in the rootvg. Refer to the mount command for details.
    Note: The mksysb command does not back up file systems mounted across an NFS network.
  • Unmount any local directories that are mounted over another local directory.

    This backup procedure backs up files twice if a local directory is mounted over another local directory in the same file system. For example, if you mount /tmp over /usr/tmp, the files in the /tmp directory are then backed up twice. This duplication might exceed the number of files a file system can hold, which can cause a future installation of the backup image to fail.

  • Use the /etc/exclude.rootvg file to list files you do not want backed up.

  • Make at least 40 MB 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 40 MB of disk space to the /tmp directory of a system with 4 MB partitions:
    chfs -a size=+80000 /tmp
  • All hardware must already be installed, including external devices, such as tape and media 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. To determine if the bos.sysmgt.sysbr fileset is installed on your system, type: 
    lslpp -l bos.sysmgt.sysbr
    If your system has the bos.sysmgt.sysbr fileset installed, continue with one of the following procedures:
    If the lslpp command does not list the bos.sysmgt.sysbr fileset, install it before continuing with the backup procedure. Refer to Optional products and service updates for instructions, or enter the following command:
    installp -agqXd device bos.sysmgt.sysbr

    where device is the location of the software; for example, /dev/cd0 for CD-ROM drive.