Browse Prior Art Database

Volume Management for Partitioned Removable Media

IP.com Disclosure Number: IPCOM000129211D
Original Publication Date: 2005-Oct-01
Included in the Prior Art Database: 2005-Oct-01
Document File: 4 page(s) / 34K

Publishing Venue

IBM

Abstract

Due to the ever increasing capacity of tape cartridges, it may be highly desirable to divide the capacity of a single physical tape cartridge into logical partitions. More importantly, it is valuable to have a system which virtualizes these partitions to the application in a transparent manner. This virtualization system is disclosed as a Volume Management Method for Partitioned Removable Media.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 28% of the total text.

Page 1 of 4

Volume Management for Partitioned Removable Media

Due to the ever increasing capacity of tape cartridges, it may be highly desirable to divide the capacity of a single physical tape cartridge into logical partitions. More importantly, it is valuable to have a system which virtualizes these partitions to the application in a transparent manner. Figure 1, below, presents a single tape which has multiple logical partitions (partition1, partition2, partition3) and a system which virtualizes the partitions.

Application

*Creates virtual VolSer for each tape partition

*Allows application to access tape partitions like virtual tapes

*Allows application to access only there own partitions = prevents access to partitions owned by other applications

Partition1 Partition2 Partition3

Figure 1: Overview of the virtualization system

The virtualization system allows effective utilization of tape cartridges across multiple applications by assigning each partition of a tape to the same or a different server or application. The benefits of the transparent virtualization of partition on tape are:

a) No changes are required to the application because the virtualization is transparent. The application still recognizes the physical tape through the virtualization system, even though it is a partition on the physical tape which the application is communicating with.
b) It facilitates effective utilization of tape cartridges by allowing different applications to storage data of differing formats on the same physical tape. In fact, some of the partitions may impersonate optical disk or hard disk, even though the physical media is tape.
c) It allows assigning partitions of tapes according to the needs of an application. An application which requires fast access to data gets the front partition on the tape (Partition1) assigned. The partitions in the further down the tape (past middle-of-tape and towards end-of-tape) can be assigned to applications which access the data rather seldom and do not require fast access.
d) It facilitates application transparent movement of data from one tape to another.
e) It facilitates application transparent replication (copy) of tapes. This copy may be a remote copy, for improved disaster recovery.

The following are methods for a system acting as a media manager to virtualize partitions residing on a physical tape medium. This allows seamless integration into existing environments. The virtualization comprises the following methods:

Virtualization System (Media Manager)

Physical Tape without partitions

Physical Tape with partitions

1

[This page contains 2 pictures or other non-text objects]

Page 2 of 4

1) Virtualizing partitions as tapes to the application
2) Policy based selection of scratch logical partitions
3) Policy based selection of scratch physical media
4) Policy based movement of partitions
5) Policy based the replication of partitions

The system is subsequently called the media management system, or simply the media ma...