Chapter 2 HPSS PlanningHPSS Installation Guide September 2002 71Release 4.5, Revision 2might be necessary by making requests to the appropriate Physical Volume Repository (PVR). ThePVL communicates directly with HPSS Movers in order to verify media labels.The PVL is not required to be co-resident with any other HPSS servers and is not a CPU-intensiveserver. With its primary duties being queuing, managing requests, and association of physicalvolumes with PVRs, the PVL should not add appreciable load to the system.In the current HPSS release, only one PVL will be supported.2.6.9 PVRThe PVR manages a set of imported cartridges, mounts and dismounts them when requested bythe PVL. It is possible for multiple HPSS PVRs to manage a single robot. This is done if it isnecessary to partition the tape drives in the robot into pools. Each tape drive in the robot is assignedto exactly one PVR. The PVRs can be configured identically and can communicate with the robotthrough the same interface.The following sections describe the considerations for the various types of PVRs supported byHPSS.2.6.9.1 STK PVR and STK RAIT PVRThe STK RAIT PVR cannot be supported at this time since STK has not yet made RAITgenerally available.The STK PVR and STK RAIT PVR communicate to the ACSLS server via STK’s SSI software.The SSI must be started before the PVR. If the SSI is started after the PVR, the PVR should bestopped and restarted.If multiple STK robots are managed, SSIs that communicates with each of the robots should beconfigured on separate CPUs. A PVR can be configured on each of the CPUs that is running an SSI.If multiple STK robots are connected and are controlled by a single Library Management Unit(LMU), a single PVR can manage the collection of robots. The PVR can be configured on any CPUthat is running an SSI.HPSS supports the device virtualization feature of the StorageTek StorageNet 6000 series of domainmanagers. This feature allows for the ability to configure a Redundant Arrays of IndependentTapes (RAIT) as an HPSS device. This capability is enabled by configuring an STK RAIT PVR foreach RAIT physical drive pool. The number of physical drives to be used by HPSS is set in the RAITPVR specific configuration, and used by the PVL when scheduling mounts of RAIT virtualvolumes. HPSS supports the following striping/parity combinations for both the 9840 and 9940virtual drives: 1+0, 2+1, 4+1, 4+2, 6+1, 6+2, 8+1, 8+2, and 8+4.
