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The TurboSTORE programs allow you to store files to a single
device or to multiple devices.
The best way to use your backup devices depends upon the characteristics
of the files that you are storing, your needs for compatibility
with other versions of MPE, and your system configuration.
The characteristics of the set of files help determine choices
(or options) for storing them. Use the following guidelines to select
the most appropriate method:
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.
If you are storing only a few files of moderate size, one
backup device such as a tape drive or DDS-format device is
sufficient.
If you are storing many files (for example, all the files in
an account, or a smaller number of very large files), a
multiple-device backup is best.
If you need to do small, fast application backups, you may
want to use the store-to-disk feature of TurboSTORE/iX 7x24
True-Online Backup (B5152AA). This allows you to quickly backup
key applications to disk files.
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:
Which and how many backup devices do you have?
If you have two or three like backup devices, use either parallel
or sequential devices. If you have at least four devices, use two
or more parallel device pools.
Do you intend to use labeled tapes?
Labeled tapes can be used with a single device and parallel
devices, but not with sequential devices. Unlabeled tapes can be
used with single, parallel, and sequential devices.
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:
ONLINE, which requires files to be closed at the
start of the backup.
ONLINE=START or ONLINE-END, which allow
files and applications to remain open throughout the entire
backup.
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.
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