HP BB118BV - StorageWorks Data Protector Express Package User's Manual & Technical Reference page 194

specific devices. You can select or exclude all tape devices, all virtual libraries, or all CD/DVD devices.
This setting is applicable only if the copy policy is set to Copy to device.
Delay This setting determines how soon following the completion of a backup job to perform the copy
operation. This timeout (or delay) is only applicable if the copy policy is set to Copy to device. Enter or
scroll to the number of minutes following a backup to start the copy operation.
Retention policy This setting determines how long data is retained on the virtual library. There are
three options for the retention policy.
• Retain data until overwritten Backup data will be retained in the virtual library until it is specifically
overwritten or erased by a backup or media job. This is a good policy to use for backups that you
want to stay "online" for fast restores from a virtual library at any time.
• Retain data until copied Backup data will be retained in the virtual library until it is successfully
copied to the copy device. In this case, space in the storage folder will be freed up after the copy
operation completes. This is a good policy to use if you want to fully optimize the use of space
in the storage folder.
• Retain data until space is needed Backup data will be retained in the virtual library until it is
successfully copied to the copy device, and the storage folder is not full. If during a subsequent backup
the storage folder becomes full, the backup data will be automatically deleted from the storage folder
to make room for the new backup. Only backups that have been successfully copied to the copy
device will be removed under this policy. This policy is the best one to use for normal operations. It
will provide the best balance of retaining backups in the virtual library and optimization of storage
folder space. Data will be removed from the storage folder following least-recently-used (LRU) order.
Copy log options Use this command to set up the log options for each copy job. Identical to the Log
options command on the Options property page of any job, you can set up a log that Data Protector
Express will save, print or e-mail to a designated user each time a copy job is run.
When a backup is copied under the D2Any2Any option, every object (file, folder, etc.) in the original
backup is copied to the copy device, and each version is recorded in the Data Protector Express catalog.
Upon normal restores, Data Protector Express will automatically select the most current version of an object
to restore, regardless of the media on which it resides. Data Protector Express makes this selection based
on the time and date that the object was backed up, and the most efficient device/media to get it from.
In the case of backups done under the D2Any2Any option, upon a restore, Data Protector Express may
discover the desired object to be on a virtual library virtual tape cartridge, on media written to the copy
device, or both places. If it is found in both places, restores will normally come from the virtual library
as it is usually the most efficient device to restore from. In the case of a backup that has not yet been
written to a copy device (either the time out has not occurred, the policy was set to Do Not Copy, or the
copy operation failed), then the restore will come from the virtual library. For cases when the data has
been removed from the virtual library (the Copy policy is selected, and either Retain data until copied
or Retain data until space is needed options is selected and data has been removed from the virtual
library), the restore will come from the copy device.
The Data Protector Express D2Any2Any option not only optimizes space usage in storage folders, it also
optimizes the use of media/storage in the copy device. When data is automatically copied from a
virtual library to the copy device, Data Protector Express remembers the source and destination media
(tapes). The D2Any2Any option "remembers" or "associates" these media so that the destination media is
retained (and not erased or overwritten) until the source media is erased or overwritten. To illustrate this
concept, consider a backup to a virtual library that's subsequently copied to a physical tape cartridge in
a physical loader. When this happens, Data Protector Express will associate the physical tape cartridge
with the virtual library virtual tape cartridge. Regardless of the retention policies on the virtual library
virtual tape cartridge, the associated physical tape cartridge must not be erased or overwritten by any
other backup or media job until Data Protector Express determines that the data can be safely overwritten.
The D2Any2Any option determines that it is safe to erase or overwrite the physical tape cartridge when
the original backup has been erased or overwritten under a regular tape rotation schedule.
The "association" described in above is very important for managing and optimizing physical media
usage.
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Working With Devices