HP B6960-96035 - Manual (Page 177)

During a restore session, the device paths are selected in the following order:
1. Paths that are on the client to which the objects are restored, if all objects are
restored to the same target client
2. Paths that were used for backup
3. Other available paths
If direct library access is enabled, local paths (paths on the destination client) are
used for library control first, regardless of the configured order.
Backward compatibility
Devices configured with previous versions of Data Protector are not reconfigured
during the upgrade and can be used as in previous releases of Data Protector without
any changes. To utilize the new multipath functionality, you must reconfigure devices
as multipath devices.
Device locking
Locking devices must cover the possibility of several applications using the same
device, as well as only Data Protector using a device by sending data and commands
to it from several systems. The purpose of locking is to ensure that only one system
at a time communicates with a device that is shared between several systems.
Device locking with multiple applications
If Data Protector and at least one other application want to use the same device from
several systems, the same (generic) device locking mechanism has to be used by
each application. This mechanism needs to work across several applications. This
mode is not currently supported by Data Protector. Should this be required, operational
rules must ensure exclusive access to all devices from only one application at a time.
Device locking within Data Protector
If Data Protector is the only application that uses a drive, but that same drive needs
to be used by several systems, Device Locking has to be used.
If Data Protector is the only application that uses a robotics control from several
systems, Data Protector handles this internally, provided the library control is in the
same cell as all the systems that need to control it. In such a case, all synchronization
of access to the device is managed by Data Protector internal control.
Concepts guide 177