Learn more on Life cycle management

Learn more on  Life cycle management

The life cycle of a cartridge describes a series of states that a cartridge can take on over the course of time. Essentially, the following events, which lead to state transitions, can be observed in the life cycle:

• Initialization Cartridges are announced to the system.

• Allocation of access rights Applications are permitted to access certain cartridges.

• Use Cartridges are used for reading and writing.

• deallocation The data on a cartridge is no longer needed; the storage space can once again be made available to other applications.

• Retirement The cartridge has reached the end of its life cycle and is removed from the system. These events directly yield a series of states for cartridges. States of media In addition to the location of the media, it is also important that storage administrators are aware of the state of the media. For example, a cartridge may not be removed from the system until no more logical volumes have been allocated to it. Otherwise, there is a

danger of data loss, because back-up software can no longer access this volume. During its life cycle (Figure 9.8) a cartridge can take on the following states:

• Undefined (unknown) No further information is known about a cartridge. This is the initial state of a cartridge before it is taken into a management system.

• Defined A cartridge is announced to the system. Information about the type, cartridge label, etc. are given, and the cartridge is thus described.

• Available In addition to the information that a cartridge exists in the system, information about whether, and where, data can be still written to the cartridge is also important. If this information is known, the cartridge is available for applications

• Allocated In order that an application can use a cartridge, suitable storage space on a cartridge

must be allocated by the system. This allocation of storage space generally leads to the placing of a volume on a partition of a cartridge. The application should be able to freely choose the identification of the volume. In general, the state of the first volume placed determines the state of the entire cartridge. To this end, as soon as the first volume has been placed on a cartridge, the state of the cartridge is set to 'allocated'.

• deallocated If the storage space (the volume) is no longer required by an application, the volume can be de-allocated. The system should then delete all information about the volume.

The application should continue to be able to reallocate the same storage space. If the

storage space is to be made available to other applications, a cartridge must be recycled.

• Recycled Depending upon system configuration, once all volumes have been removed from a cartridge the entire storage space can be made available to other applications.

• Purged A cartridge, and all information about this cartridge, is completely removed from the system. In general, this state is reached at the end of a cartridge's life cycle. Typically, this state exists only for a short time, since the cartridge is immediately placed in the undefined state.

Policy-based life cycle management Certain tasks should be automated so that as little manual intervention as possible is required during the management of the data carriers. In life cycle management, some tasks positively demand to be performed automatically. These include:

• the monitoring of retention periods;

• transportation to the next storage location (movement or rotation);

• the copying of media when it reaches a certain age;

• the deletion of media at the end of the storage period;

• the recycling or automatic removal of the cartridge from the system.

The individual parameters for the automated tasks are specified by suitable policies.

Individual cartridges, or groups of cartridges, are assigned suitable policies.