HP StoreOnce B6000 Use Manual page 17

A front-end script will handle the "notification" and feed a "incoming" queue. This frontend is
depended on the device (VLS – email processing, D2D XML polling).
The backend processes the incoming queue and distributes the media to import to the available
devices. The backend will maintain a log of import jobs and re-queue jobs in case of failures.
Replication Window
A configurable period of time within the D2D & VLS systems during which replication is not allowed
to take place. Primarily this is to ensure available WAN bandwidth is not oversubscribed during peak
periods of demand which might slow down application performance.
Seeding/Initializing
This term is used to define the process of "synchronizing" the two D2D or VLS appliances with the
correct data prior to low bandwidth replication commencing. Because low bandwidth replication only
transfers differences the Virtual tape libraries have to have the baseline/reference data established
before low bandwidth replication can work.
Importing/Exporting
For Seeding large quantities of data we cannot use a low bandwidth link, so physical tape or co-
location is used to allow the source and target devices to be synchronized. If physical tape is used an
export and import process is used to get data out of and back into the D2D or VLS devices.
Tape Offload
On D2D devices there is an in-built tape offload utility accessible from the user interface that allows
scheduled copies of the replicated data onto physical tape device connected directly to the D2D by
SCSI or SAS host bus adapter inside the D2D.