Back up terminologies #4

• Remote store
  Backing up data to an offsite permanent backup facility, either directly from the live data source or else from an intermediate near store device.
• Restore time
  The amount of time required to bring a desired data set back from the backup media.
• Retention time
  The amount of time in which a given set of data will remain available for restore. Some backup products rely on daily copies of data and measure retention in terms of days. Others retain a number of copies of data changes regardless of the amount of time.
• Site-to-site backup
  Backup, over the internet, to an offsite location under the user's control. Similar to remote backup except that the owner of the data maintains control of the storage location.
• Synthetic backup
  A term used by NetBackup for a restorable backup image that is synthesized on the backup server from a previous full backup and all the incremental backups since then. It is equivalent to what a full backup would be if it were taken at the time of the last incremental backup.
• Tape library
  A storage device which contains tape drives, slots to hold tape cartridges, a barcode reader to identify tape cartridges and an automated method for physically moving tapes within the device. These devices can store immense amounts of data.
• True image restore
  A term used by NetBackup and Backup Exec for the collection of file deletion and file movement records so that an accurate restore can be performed. For instance, consider a system that has a directory with 5 documents in it on Friday. On Saturday, the system gets a full backup that includes those 5 documents. On Monday, the owner of those documents deletes 2 of them and updates 1 of the 3 remaining. That updated document gets backed up as part of The Monday night incremental backup. On Tuesday afternoon the system crashes. If we perform a normal restore of the full backup from Saturday and the incremental backup from Monday to the fresh system, we will have restored the 2 documents that were intentionally deleted. True image restore keeps track of the deletions with each incremental backup and prevents the deleted files from being inappropriately restored.
• Trusted paper key
  A machine-readable print of a cryptographic key.
• Virtual Tape Library (VTL)
  A storage device that appears to be a tape library to backup software, but actually stores data by some other means. A VTL can be configured as a temporary storage location before data is actually sent to real tapes or it can be the final storage location itself.