Fabric OS Encryption Administrator's Guide

Fabric OS Encryption Administrator’s Guide 77

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Re-balancing the encryption engine

If you are currently using encryption and running Fabric OS 6.3.x or earlier, you are hosting tape

and disk target containers on different encryption switches or blades. Beginning with Fabric

OS 6.4, disk and tape target containers can be hosted on the same switch or blade. Hosting both

disk and tape target containers on the same switch or blade might result in a drop in throughput,

but it can reduce cost by reducing the number of switches or blades needed to support encrypted

I/O in environments that use both disk and tape.

The throughput drop can be mitigated by re-balancing the tape and disk target containers across

the encryption engine. This ensures that the tape and disk target containers are distributed within

the encryption engine for maximum throughput.

All nodes within an encryption group must be upgraded to Fabric OS 6.4 or later to support hosting

disk and tape target containers on the same encryption engine. If any node within an encryption

group is running an earlier release, disk and tape containers must continue to be hosted on

separate encryption engines.

During re-balancing operations, be aware of the following:

• You might notice a slight disruption in Disk I/O. In some cases, manual intervention may be

needed.

• Backup jobs to tapes might need to be restarted after re-balancing is completed.

To determine if re-balancing is recommended for an encryption engine, check the encryption

engine properties. Beginning with Fabric OS 6.4, a field is added that indicates whether or not

re-balancing is recommended.

You might be prompted to re-balance during the following operations:

• When adding a new disk or tape target container.

• When removing an existing disk or tape target container.

• After failover to a backup encryption engine in an HA cluster.

• After a failed encryption engine in an HA cluster is recovered, and failback processing has

occurred.

To re-balance an encryption engine, complete the following steps:

1. Select Configure > Encryption from the menu task bar.

The Encryption Center dialog box displays.

2. Select an engine, then select Engine > Re-Balance from the menu task bar, or right click an

engine and select Re-Balance.

A warning message displays, noting the potential disruption of disk and tape I/O, and that the

operation may take several minutes.

3. Click Yes to begin re-balancing.