News
Managing Media in Networked Environments
Michael Kramer
B&L Associates, Inc.
220 Reservoir Street, Ste. 15
Needham, MA 02494 USA
(781) 444-1404/5805 fax
mkramer@bandl.com
Retention Management
Retentions determine how long a tape management system tracks a volume that has been logged into the database. Retention definitions for volume names should be very flexible and be based on days, generations, or any combination of the two. A tape management system should allow for both standard and alternate retentions for the same volume name. This is very useful in daily operations. For example, a piece of media created at the end of a month may have a very different retention than a piece of media created on a daily basis even though they have the same volume name.
Vault Management
ault management tells an operator where to store media and when to move the media to a different location. A tape management system should provide automatic movement notification for movement between multiple sites and different storage modes within those sites. The system should then allow for movement reconciliation to make sure only the correct media is moved.
Movements define where media should reside at different stages of its life. This feature is critical for satisfactory disaster recovery planning. Similar to retention management, vault management is based upon days, generations, or combinations of the two. Like retention management, the vault management system should allow for both standard and alternate movements for the same volume name. For example, a piece of media created at the end of a month may move on a different cycle than a piece of media created on a daily basis even though they have the same volume name. Media can be stored by serial number, slot or box assignment. These methods may be used simultaneously, permitting maximum flexibility to meet unique storage requirements.
Relationship Processing
Relationship processing allows one volume name to control the retention and movement of another volume name. This is a critical feature for incremental backups that must be maintained in conjunction with a full backup. A tape management system should keep these related volume names together, automatically.
Virtual Media Handling
Virtual media is where many generations of a volume name are put on the same piece of media. For example, Monday's, Tuesday's, and Wednesday's backups may all be "stacked" on the same piece of media, but each one is a different data section on the media and must be retained and tracked as a separate entity. With the advent of new media, such as LTO tape, this is becoming more common and desirable since it makes better use of the media. New tape management systems are designed with technological advances in mind and handle them without any disruption.
Purge Protection
A tape management system must notify the user about the status of a piece of media before it is mounted on the drive to protect against purging the data. This protects the information and allows the operator to save time when looking for the appropriate information to be retrieved.
Security
A tape management system lets administrators retain maximum control over system security. User access can be restricted by user codes, hosts, volume names, or any combination of the three. Further, users can be restricted to specific functions within their domain. This two-tier security allows the system administrator to restrict user access to a particular subset of the media and functions, while allowing all media to reside in one central database.
Inventory Control
Inventory control allows the user to know exactly where all the media is and to reconcile the physical media against the media management system's database. These features utilize bar code technology to streamline the process. Inventory reports show discrepancies between the data collected and the database information.
System managers must also determine which systems and data centers are logical backup sites and what kind of aggregation makes sense. There is a necessary trade-off between having a small number of centralized offline tape management sites and a greater number with more local control. The fibre channel facilitates flexibility by creating a single, integrated network that enables the efficient consolidation or distribution of data for tape management purposes.
Staffing is also an issue. Full-time dedicated staff can be justified for some data center locations. Wherever possible, tape management should be handled by librarians who are dedicated to offline storage functions. For smaller operations, where it is not a full-time function, the responsibility for offline tape management must be clearly defined and should be included in formal job descriptions. Regardless, every company should have a tape management director who is charged with the responsibility of defining and overseeing the policies and procedures for everyone who touches offline media across the enterprise.
