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Backing Up to a Group of Parallel Data CarriersLocate this document in the navigation structure

Use

To speed up the backup process, you can back up your data to several data carriers in parallel (subsequently called a group of parallel data carriers). Note that you cannot back up log entries to a group of parallel data carriers.

Most backup options are available for backups to a group of parallel data carriers as well: you can back up data to the local computer or to remote computers, you can use tape drives and you can connect third-party backup tools.

You combine backups to different types of data carriers. Because the data is automatically distributed between the data carriers during the backup process, you can also combine carriers with different write speeds without difficulty.

The system stores the information on how many data carriers were used for the backup on the data carrier that was finished last. All other data carriers only contain details of the successful write process of the backup data.

A parallel backup is not fundamentally different from a sequential backup:

  • During a sequential backup, you specify the backup template at the start of the backup operation. When the specified data carrier is full, the system asks you to specify the next backup template or to specify the operating system path (including the name of the file or pipe) where the next data carrier can be accessed.

  • Parallel backups are similar, but use several data carriers in parallel. The system requests a new data carrier for the first data carrier that is full, and proceeds accordingly for each individual data carrier until the data is completely backed up. Therefore, a parallel backup is a combination of parallel and sequential backup operations when the number of data carriers needed exceeds the number of parallel data carriers.

Example

For your backup, you need the storage space of 7 tapes. If you start the backup with 5 tape drives, then the 5 tapes are written simultaneously at first (parallel backup). The first tape drive with a full tape requests a new tape. Data is then backed up to the sixth tape sequentially. All other tape drives continue simultaneously (parallel backup) until another tape drive is full. This drive then requests a new tape (number 7).

When the system requests the next data carrier, you must choose one of the following options to continue and complete the backup:

  • Insert the next data carrier.

  • Tell the system to continue writing to the remaining data carriers only.

  • If Database Manager CLI is used, then you can specify the AUTOIGNORE option at the start of the backup process. This allows the system to continue writing to the remaining data carriers without asking for confirmation.

    Caution

    Only use this option when you are sure that the complete amount of backup data will fit on the first set of data carriers in the group, and no succeeding data carriers will be required.

    You can simplify background backups in Database Manager CLI using the AUTOIGNORE option.

    Example

    You schedule regular nightly data backups for your system. The memory of 5 tapes is required for your backup. You start the backup process in the evening and specify the AUTOIGNORE option. If you carry out a backup with 5 tape drives, then the 5 tapes are written simultaneously at first (parallel backup). The first tape drive with a full tape stops, but all remaining tape drives continue until all the data is backed up.

Prerequisites
Procedure

Use the normal functions for data backup.

More information: Backing Up Data

Result

You now have a data backup consisting of several data carriers. After a database failure, you can restore this backup sequentially or in parallel.