Backing Up Data › Backup Staging Methods › How Backup to Disk to Tape Works › Disk Staging Capabilities

Disk Staging Capabilities

Using disk staging to store backup data provides the following capabilities:

• File System Device Capacity Management--Arcserve Backup lets you specify minimum capacity and maximum capacity thresholds of the file system device. The maximum threshold can be represented as either an absolute value or as a percentage of the capacity of the volume.
• Ensures that Arcserve Backup does not use the full capacity of a disk--A backup job will fail when writing to a file system device if the total disk space used exceeds the maximum threshold.

  Important! File System Devices (FSD) that are part of a staging group cannot be erased or formatted using the corresponding utility from the Device Manager window. To prevent accidental erasing or formatting of an FSD prior to the staged data being migrated to a final destination media, the Erase and Format toolbar buttons on the Device Manager window are disabled. If you want to erase or format the FSD, you can either use the command line (ca_devmgr) or disable the staging option for the selected FSD.

• Increases your overall backup success rate--You can define staging policies that let you create makeup jobs that back up directly to tape if an exceeds maximum threshold condition occurs or to create a makeup job on hold if a data migration failure occurs.
• Pause Data Migration--Arcserve Backup lets you pause the migration of data from the FSD to the final destination (tape) by enabling the Pause Data Migration option. This feature allows you to continue backing up to the FSD, but pause the migration from the FSD to the final destination in case the tape library is scheduled for maintenance or has hardware problems.
• Simultaneous Streaming--Simultaneous streaming is a process that divides your backup jobs into several subjobs that run simultaneously. Disk staging allows you to utilize the simultaneous streaming feature to send multiple streams of data to the temporary staging device (FSD) at the same time. Since the work is split up among several different streams (for concurrent writing to the FSD), simultaneous streaming-enabled backup jobs can be completed significantly faster than regular backup jobs. Simultaneous streaming also provides the capability to restore data while backup jobs are running.
• SnapLock Support--SnapLock™ is technology from Network Appliance that provides non-erasable, non-rewritable, Write Once Read Many (WORM) data protection. Arcserve Backup lets you use SnapLock protection on the backup operation. When you back up data with SnapLock protection enabled, you cannot purge or over-write the backed up data until the specified retention time elapses. This ensures that the data on the FSD cannot be deleted by any user, thus providing WORM support on disk with a retention time out. The retention time for the enabled SnapLock protection is determined by the specified settings for the staging purge policies.

  Note: The device must support SnapLock technology. If you enable SnapLock on a device that does not support SnapLock WORM protection, Arcserve Backup write-protects the data, however, the data can be deleted from the device.

• Copy Image Tracking--Arcserve Backup provides the capability to track copied images on different media. As a result, the merging of catalogs only has to be performed one time, and then all sessions which are copies of each other would point to the same catalogs.
• Flexible Restore Options--During the time period that the backed-up data is located both on the final destination media (tape) and on the FSD (prior to purging), Arcserve Backup provides you with a choice for selecting the source for restoring the data. If the backup image is located on both the FSD and the final destination, you can choose where to restore it from.
• Smart Restore--Arcserve Backup provides a transparent Smart Restore feature that lets you restore backup data from multiple locations. If a media or drive error occurs during the restore process, from either the FSD or from the final destination media, Arcserve Backup internally finds the alternate media and starts restoring the data from the alternate media. Smart Restore helps to increases the success rate of restores in the event hardware problems occur while the job is running.
• Optimize Restore Option--If Arcserve Backup detects duplicate backup sessions, where one session resides on tape media and another session resides on an FSD, the Optimize Restore option lets you restore the data from the session that resides on the FSD.
• Command Line Support--Arcserve Backup lets you create backups to FSDs using either the graphical user interface (GUI) or the command line utility. In the event that a copy-to-tape operation fails, you can use the Query tool to analyze the file and session contents on the FSD. If you need to purge sessions from the FSDs, you can use the Purge tool to remove data and free extra space on the FSDs.
• Disk Staging Reports--Arcserve Backup lets you generate reports that are dedicated to disk staging backups. Using these reports you can find the status of backup sessions, whether a session was copied, when the session was copied, where the session was copied, whether the session was SnapLocked, when the session will be purged from the FSD, and other valuable information.