How to Use Disk Staging to Manage Archive Data

The following list describes how you can use staging to manage archive data.

• Using disk staging you can archive data to disk staging devices that are used as a temporary staging area. A staging job can divide your archive job into several subjobs that run simultaneously. Disk staging lets you use simultaneous streaming to send multiple streams of data to the disk staging device. Since the data is split among several different streams, archive jobs with simultaneous streaming enabled can be completed significantly faster than regular archive jobs.
• You can then migrate (copy) the data from the disk staging device to a final storage media (or from disk to tape). As a result, the tape drive can be kept streaming, thereby minimizing the shoeshine effect (starting, stopping, and repositioning the tape), and increasing both the life expectancy and efficiency of the tape drive. While the archive image is still on the disk staging device, data can be restored directly from the disk staging device. The restore time is significantly reduced because restoring data from disk is generally faster than restoring from a tape (no delays due to tape load and seek latency).
• During the archive-to-disk staging device process, if the disk staging device gets full or reaches the specified maximum threshold, Arcserve Backup lets you create makeup jobs which would then archive the data directly to the final destination after the staging archive job fails. This increases the success rate of archives. In addition, if there are any errors during the copy-to-final destination process, Arcserve Backup lets you create makeup jobs.
• Note: Under disk full conditions, the makeup job created to archive the data to tape will always try to use a blank tape or a media from a scratch set. It will never try to append to an existing media.
• The archive images are kept on the disk staging device until the retention time expires (as determined by the specified purge policy). At that time, Arcserve Backup automatically purges the data from the disk staging device, and reclaims disk space so that archives can continue.