When Would I Restore From An Exported Cartridge; Disadvantages Of Export; Compression; Cartridge Import - HP StorageWorks D2D100 - Backup System User Manual

When would I restore from an exported cartridge?

Restoring from an "exported" cartridge has a higher likelihood than from a copied cartridge, because
the data no longer resides on the HP D2D Backup System. If a restore from an "exported" cartridge is
required, the backup application will ask for the cartridge to be re-imported into the HP D2D before it can
be used for restore. Exported cartridges may also be used for disaster recovery, as with copied cartridges.

Disadvantages of Export

1. Restores may take longer if a physical cartridge is required for the restore.
2.
Backup applications may require the exported cartridge for the next job in their rotation scheme.

Compression

When you are moving data from the HP D2D to physical tape, it is important to be aware that the
cartridge maximum size is the native size (without compression). HP StorageWorks tape drives apply
hardware compression, therefore, the data from the HP D2D Backup System is likely to require less space
on a physical tape cartridge. When moving data to a physical cartridge for off-site storage, there is no
need for concern if the data seems to utilize less space.
The capacity quoted for physical media assumes that the tape drive will be able to compress your data
and reduce the file sizes by 50%, but this can be achieved only if your data is not already compressed.
For example, JPEG pictures, movies, music or ZIP files, are already in compressed formats: spreadsheets,
text files, high-resolution graphics are not. Most users have a mixture of compressed and uncompressed
data and seldom achieve 50% compression.
Some users may choose to enable software compression from their backup application to increase
the storage space available to the backup application, but this can make backup jobs slower to run.
However, once software compression has been applied, the data is not further compressed when it is
exported to a physical tape directly attached to the HP D2D Backup System. This ensures that the user
knows exactly how much physical cartridge space is required for export or copy.

Cartridge import

The Web interface on the HP D2D is used to Import cartridge data from the attached tape storage device
to the mail slot on the HP D2D Backup System. The backup application on the host is used to move the
data from the mail slot back into one of the library slots.
D2D Backup System HP D2D2503
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