 |
» |
|
|
|
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 or single magneto-optical device 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. Magneto-optical devices cannot be used to
perform labeled backups.
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.
|
