342 IBM ProtecTIER Implementation and Best Practices Guide
Aborting replication tasks
Aborting replication tasks removes them from the list of pending and running tasks. These
tasks automatically re-execute if the specific cartridge is:
򐂰 Appended
򐂰 Ejected from the library
򐂰 Selected for manual execution
To prevent these replication tasks from re-executing, mark those cartridges as
either on the ProtecTIER server, or by the backup application. These cartridges are not used
for further backups, and therefore do not replicate the backlog. New (scratch) sets of
cartridges are used for subsequent backups, and do not contain backlog data that does not
need to be replicated.
21.4 Many-to-one replication
ProtecTIER many-to-one replication offers the following enhanced features and benefits:
򐂰 Setting replication performance limits: The most significant many-to-one replication
enhanced feature is the capability to set system-wide physical and nominal limits for the
maximum replication transfer rate allowed in the network for a specific repository. The
performance limit reflects the overall resource consumption of the system. The network
transfer rate reflects the performance limits.
򐂰 Enhancements to the replication rate control mechanism: Currently, the replication rate
control (RRC) is used when a user does not provide a time frame and the system
replicates continuously. The
rate calculation determines the maximum rate possible in
both levels of system usage (IDLE and BUSY), and normalizes the rate accordingly.
򐂰 Reserving local-backup-only space for the hub repository: You can use this enhancement
to exclusively assign a portion of a hub repository for local backups. In large deployments
with many spokes replicating, capacity management might cause replication to occupy all
the space in hub repository.
Because a backup has higher priority over replication, this enhancement was added to
ensure that capacity is reserved only for local backup. Replication cannot be written to this
portion of the hub repository. Error notifications display if the repository hub areas
reserved for local backup or replication are reaching maximum capacity.
򐂰 Enhanced monitoring of repository space consumption: A new GUI feature that provides
an at-a-glance view of the proportion of the repository data, replication data, local backup
data, and free space.
21.4.1 Planning for replication
ProtecTIER systems with replication require more planning than systems used only as a local
VTL. When a multiple-site, many-to-one topology is deployed, the entire configuration,
including all spokes and hub environments, are considered.
Tip: To resume I/O activity, use different barcodes. Because the earlier data on the older
cartridges is replicated before the new data, the backlog is too large to manage. Using a
different set of barcodes allows the new data to be replicated, and you can skip replication
of the data from the old cartridges.

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