HP BB118BV - StorageWorks Data Protector Express Package User's Manual & Technical Reference page 195

For example, without this capability each backup to the virtual library under the D2Any2Any option
would eventually lead to consuming another physical tape cartridge, ultimately consuming all available
physical media. Knowing when it is safe to reuse physical media is critical for a cost effective automated
disk-to-disk-to-any solution.
The "association" is accomplished by Data Protector Express when the copy operation is successfully
performed. When this happens, the virtual tape cartridge (media) for the virtual library is converted
to a D2D media folder, and the physical media where the backup was copied is moved into this
folder. A D2D media folder acts as both a piece of media and a media folder. If the D2D media
folder is erased or overwritten, this is the signal to Data Protector Express that the associated physical
media can be safely erased or overwritten. If you want to retain the backups on the associated physical
media indefinitely, then simply move the associated physical media out of the D2D media folder. In this
case, the associated physical media will not be erased or overwritten unless you specifically create a
backup or media job to do that.
Example 1. Virtual backups of a laptop hard disk while an employee travels
An employee who uses a laptop travels frequently on business. While away from the office he uses Data
Protector Express to run daily incremental backups of data files to a local virtual device. These incremental
backups are relatively small, but they provide him with access to backups of his work in the event that he
deletes his work while away from the office and unable to back up his system on the network. When he
returns to the office he connects the computer back to the network, runs a full backup to physical backup
devices and copies the incremental backups from virtual to physical media.
In this example, the backups on virtual media have become obsolete since they are now available on
physical media.
Example 2. Limited physical backup devices
A small company has a limited number of backup devices. Recently the company has expanded and
now has more employees backing up data to these physical devices. Backups are beginning to exceed
the physical media capacity. Some backups halt during processing so that an operator can insert
additional media into the devices. Backups that could be performed unattended now require an
operator to be present.
To ease the burden being placed on both the physical backup devices and the IT support staff, the
company instructs the Data Protector Express administrator to create a virtual device on the network. The
backup jobs are modified to use this virtual device as the backup destination. If D2Any2Any backups
are available, you can create rules that transfer the backups from virtual devices to physical media on a
staggered schedule. This schedule permits the IT staff to monitor the physical media, swapping out full
media as necessary, and keeping the backups running smoothly. In standard D2D backups, you can
copy data from virtual media manually.
In this example, a growing company needs the capacity of an expensive library but cannot yet include it
in their budget. By creating a virtual library, or a series of them, the company gains the advantages of
the larger storage capacity of a library without breaking its budget.
Example 3. Creating redundant backups to ease data restore operations
A large company wants to develop a data protection system that includes full data protection but that also
eases the burdens on their IT support staff when minor data restore jobs arise. To do this the company
creates a network virtual library and directs all backups to this destination instead of to physical media.
Each week these backups are transferred to physical media. Rules are set in Data Protector Express to
retain the backup data on the virtual media for a minimum of two weeks before deleting it if the virtual
storage is required for current backups.
An employee discovers that a critical data file has been damaged, so she creates a restore job in Data
Protector Express. Since Data Protector Express tracks of the location of each backup version in the Data
Protector Express catalog, the restore job sees that identical versions of the file exist both on virtual and
physical media. The physical media is no longer in a physical device and an IT staff member would have
to locate it to do a restore from it. Instead of waiting for another staff member to locate the physical media,
Data Protector Express restores the file from the virtual media and the employee can continue her work.
In this example, the company created redundant backups that made it possible for an employee to
restore data files without involving support staff.
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User's Guide and Technical Reference