IBM Spectrum Archive Enterprise Edition

The components of the IBM Spectrum Archive™ Enterprise Edition are HSM, MMM, and Spectrum Archive LE+, working with the IBM Spectrum Scale™ GPFS™ file system.

Spectrum Archive Enterprise Edition component overview

The Spectrum Archive Enterprise Edition contains multiple components that enable IBM Spectrum Scale to migrate and recall data from the Spectrum Archive tape tier. Files are migrated and recalled by using the Spectrum Archive Enterprise Edition components that are shown in Figure 1 .

Figure 1 shows the components that make up the Spectrum Archive Enterprise Edition with a single tape library attached. The components in this figure are shown with IBM Spectrum Scale configured on separate nodes for maximum scalability.

Figure 1. Components of Spectrum Archive EE with separate Spectrum Scale nodes

This image shows the components of the Spectrum Archive EE system, which are HSM, MMM, and Spectrum Archive LE+. Spectrum Archive EE is attached to IBM Spectrum Scale nodes. Other IBM Spectrum Scale nodes exist that are separate from the nodes in the Spectrum Archive EE cluster.

Hierarchical Storage Manager (HSM)

The HSM component of the Spectrum Archive Enterprise Edition uses Spectrum Protect for Space Management for migration and recall activities. It enables automatic migration of eligible files from Spectrum Scale to the Spectrum Archive tape tier, and automatic recall of migrated files occurs as files are accessed. Users can also migrate and recall specific files. The migration process reclaims space on the local file system for more active files.

The HSM component is automatically started during the Spectrum Archive Enterprise Edition configuration process. To verify that it is running, refer to the topic Retrieving the status of Spectrum Archive Enterprise Edition components in the Related information section.

Note: The Spectrum Archive Enterprise Edition package includes a customized Spectrum Protect for Space Management client. No other Tivoli® Storage Manager licensed function is entitled by the Spectrum Archive Enterprise Edition license.

Multi-tape management module (MMM)

The multi-tape management module (MMM) is a service that runs on the Spectrum Archive EE control node. The MMM service implements policy-based cartridge selection and maintains the state of all of the resources that are available in the system.There is one control node per tape library.

The scheduler component of the control node uses policy-based cartridge selection to schedule and process job requests, such as migration and recall requests, which are fulfilled by using available system nodes and tape resources. The following tasks are done by the scheduler:

Choosing a job from the job queue
Choosing an appropriate tape cartridge and tape drive to handle the work
Starting the job

The control node also manages the creation of replicas across multiple tape libraries. For example, when the ltfsee migrate command specifies making replicas of files in multiple tape libraries, the command accesses the control node that manages the tape pool for the primary copy. The control node puts the copy job in the job queue for the primary tape library, then passes the secondary copy job to the control node for the second library. The second control node puts the copy job in the job queue for the second library.

When the scheduler component of the control node selects a tape and tape drive for a migration job, it manages the following conditions:

If the migration is to a tape pool, the drive must belong to the node group that owns the tape pool.
If a format generation property is defined for a tape pool, the tape cartridge must be formatted as that generation, and the tape drive must support that format.
The number of tape drives that are being used for migration to a tape pool at one time must not exceed the defined mount limit.
If there are multiple candidate tapes available for selection, the scheduler tries to choose a tape that is mounted on an available drive.

When the scheduler selects a tape and tape drive for jobs other than migration, it makes the following choices:

Choosing an available drive in the node group that owns the tape and tape pool.
Choosing the drive that has the drive attribute for the job.

When the control node scheduler selects a tape for recall, it manages the following conditions:

If the file has a replica, the scheduler chooses the primary copy. The first tape pool that is used by the migration process contains the primary copy.
If the primary copy cannot be accessed, the scheduler retries the recall task with replicas and redundant copies.

Other functions that are provided by the control node include the following items:

Maintaining a catalog of all known drives that are assigned to each Spectrum Archive EE node in the system
Maintaining a catalog of tape cartridges in the tape library
Maintaining an estimate of the free space on each cartridge
Allocating space on cartridges for new data

The control node is started when the Spectrum Archive Enterprise Edition is started with the ltfsee start command. The control node runs on only one Spectrum Archive Enterprise Edition node at a time. If the service stops unexpectedly, it is possible to manually start the control node on another node. Several operations, including migration and recall, fail if the control node services stop. If SNMP traps are enabled, a notification is sent when the control node services start or stop. Refer to Starting and stopping the Spectrum Archive Enterprise Edition and Monitoring the system with SNMP in the Related information section.

Spectrum Archive LE+

This component is the tape tier of the Spectrum Archive Enterprise Edition. It is an enhanced version of the Spectrum Archive Library Edition that is designed to work with the Enterprise Edition. The Spectrum Archive LE+ component is installed on all of the Spectrum Scale nodes that are connected to the LTFS library and is the migration target for Spectrum Scale. The Spectrum Archive LE+ component accesses the recording space on tape cartridges through its file system interface. It and handles the user data as file objects and associated metadata in its namespace.

The Spectrum Archive LE+ component must be started manually by mounting the library on each node. Refer to the topic Requirements for starting the Spectrum Archive Enterprise Edition in the Related information section.

Note: The Spectrum Archive LE+ component is not a separate product. It is only a component of the Spectrum Archive Enterprise Edition.