Determining Your Backup Strategy

How many files do you need to back up?

Generally, the more files in the fileset, it is to your advantage to use multiple devices or a high capacity storage device such as a magneto-optical disk device.

Do the backup files need to be compatible with another system?

Compatibility with other versions of MPE limits your choices. If you need to create STORE tapes that are compatible with MPE V/E, you must use the TRANSPORT option. This restricts you to a subset of the available STORE commands, and allows you to only store to one device. If you need to take files from a MPE/iX 5.0 or later system to a pre-5.0 system, you should use the TRANSPORT=MPEXL option. This ensures that various POSIX features are correctly translated to a pre-POSIX version of MPE.

Does your system configuration include multiple backup devices?

If you do not need to create backups compatible with older versions of MPE, then your system configuration is the most important determining factor of which multiple-device method to use. Use the following guidelines to select a method:

Do you have user volumesets or mirrored volume sets on your system?

If you use volume sets for application and volume management, then you may want to use the ONVS option of STORE. This option allows you to back up all files on a particular volumeset, including the system directory information for the volumeset. Doing backups on a volumeset basis can help reduce downtime by breaking up a large backup into individual volumeset backups. Recovery time is also increased, since you can restore from backups that only contain files for a particular volumeset.

If you are using mirrored disks, and you do not have the TurboSTORE/iX 7x24 True-Online Backup product, you can use the SPLITVS option of STORE to back up a split copy of your mirrored set.

However, if you are using TurboSTORE/iX 7x24 True-Online Backup, the recommended way of performing mirrored disk backups is to use either the ONLINE=START or ONLINE=END option. TurboSTORE/iX 7x24 True-Online Backup allows you to back up your volumeset without losing the protection of the mirrored disks, and without closing down files.

Do you have critical applications that need to be available 24 hours a day?

If your system environment includes applications that need to be available on a 24-hour basis, you should use TurboSTORE/iX 7x24 True-Online Backup. This product provides three different online backup options:

Using any of the online backup options means that you do not have to dedicate the system to doing backups. Using the new 7x24 True-Online backup option allows you to backup files and applications while users are accessing them. Using the normal online option requires files being backed up to be closed for a short time at the start of the backup. Normal access can be resumed once the actual backup begins.

The TurboSTORE/iX 7x24 True-Online Backup options allow you to schedule the sync point for the backup at either the beginning of the backup (ONLINE=START) or at the end of the backup (ONLINE=END). The backup's sync point is the point when the state of all files being backed up is synchronized. When the backup is restored, all files are restored to the state they were in at the time of the sync point. TurboSTORE also synchronizes any TurboIMAGE or ALLBASE/SQL databases being stored, ensuring that consistent copies of the databases are written to the backup.

See Chapter 7 for more information on using the new TurboSTORE/iX 7x24 True-Online Backup feature.