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Procedure documentation Setting Up Tape Devices for Logical-Log Backup (ontape)  Locate the document in its SAP Library structure

Use

You need to set up tape devices – that is, tape drives – for logical-log backup of your Informix database with ontape .

Procedure

  1. Decide the number of tape drives.

    2. SAP recommends that you have at least two tape drives, one for archives and one for logical-log backups. Otherwise, if your logical logs fill up when you are performing an archive, the database might stop processing. At the minimum, you must have one tape drive for logical-log backup.

  2. Consider the speed of tape drives.

    3. Your drives must be fast enough to cope with the maximum rate at which the logical-log fills. Local drives are more likely to cope than remote ones.

  3. If using continuous logical-log backup, dedicate a storage drive.

    4. For continuous logical-log backup, you need to dedicate a terminal and a tape drive to the logical-log backup. You should not use a remote drive for logical-log backup because it is less secure than a local one.

  4. Define the tape drives.

You need to define at least the device LTAPEDEV with a suitable physical device for logical-log backup. Refer to Configuring ontape.

Caution

Do not use /dev/null (UNIX) or nul (NT) for LTAPEDEV if you want to perform a restore of your system up to the time of failure.

If you specify a null value for LTAPEDEV , the logical-log files are marked as backed up as soon as they are full. Therefore, they cannot be backed up and the transactions recorded in these logs cannot be used for a logical restore.

 

 

See also:

Informix documentation at http://www.informix.com