Performing logical log backups

The following are the procedures for performing logical log backups.

This topic contains steps for Windows® and UNIX®.

Windows

Procedure

  1. Ensure that you are an Informix-Admin group member and working as local administrator to perform this command.

    You must run this command on the machine where the Informix server resides.

  2. Set the environment variables for the Informix directory.

    > CCM_HOME\informix\setenv.cmd

  3. Mount the tape drive specified in the LTAPEDEV parameter, and then insert a blank tape.
  4. Run the ontape command to back up the logical log files.
    CAUTION:
    If you choose to back up logical log files, you must ensure that the media to which the logical logs are written are always available and have free space. If the backup is not able to write data onto the media and the logical logs are full, the database server does not operate normally. The database freezes until the logical log files are writable.

    To back up the logical log files continuously, type:

    > ontape /c

    Use this type of backup because it requires a tape device to be available at all times.

    To back up the logical log files explicitly, type:

    > ontape /a

  5. Swap and label the tape when it is full.

    Clearly label the tapes so that later when you restore the Informix server, the appropriate tapes can be identified easily.

    An example of good labeling follows:

    Date: April 20, 2006
    Server: servername
    Type: logical log backup
    Log numbers: 3 - 5
    Tape sequence number: 1

UNIX

Procedure

  1. Log on the database server as user root.
  2. Set user to informix.
    root# su - informix
    Password: *****

    If you did not set up CCM_HOME and PATH for user informix during installation, set these environment variables now. See Setting environment variables for UNIX.

  3. Set the environment variables for the Informix directory.
    $ INFORMIXDIR=$CCM_HOME/informix; export INFORMIXDIR
    $ PATH=$CCM_HOME/bin:$INFORMIXDIR/bin:$PATH; export PATH
    $ ONCONFIG=$servername; export ONCONFIG
    $ INFORMIXSERVER=$servername; export INFORMIXSERVER
  4. Mount the tape drive specified in the LTAPEDEV parameter, and then insert a blank tape (or use the backup file).
  5. Start the backup command.
    CAUTION:
    Ensure that the device to which the logical logs are written is always available and has free space. If the backup cannot write data to the backup device and the logical logs are full, the database server cannot operate normally. The database hangs until the logical log files are writable again.
    1. Back up the logical log files continuously by running the following command:

      $ ontape -c

    2. Back up the logical log files explicitly by running the following command:

      $ ontape -a

  6. Swap and label the tape when it is full.

    Label the tapes clearly so that later, when you restore the database server, you can identify the appropriate tapes easily. An example of good labeling is as follows:

    Date: April 20, 2006
    Server: servername
    Type: logical log backup
    Log numbers: 3 - 5
    Tape sequence number: 1
  7. Exit from user informix.

Feedback