IBM HPSS manual Hpss Filesystem, Setup Tape Libraries Special LTO Considerations

/db2/mirror-backups/subsys1

4.2.2. HPSS Filesystem

Configure /var/hpss as a separate file system on each HPSS server node. This filesystem will store HPSS configuration files, log files, MPS reports, and other HPSS related files. It is recommended that this filesystem be at least 1GB in size.

Configure /var/hpss/adm/core as a separate file system on each HPSS server node. If an HPSS process fails and creates a core file, it will be placed in this location. It is recommended that this filesystem be configured with at least 2GBs of disk space on Server nodes and 1 GB on Mover nodes.

Configure /var/hpss/hpssdb as a separate file system on the HPSS core server node. This filesystem stores the HPSS DB2 instance configuration information as well as the 'CFG' database tables. This filesystem should be created with at least 1GB of disk storage and, like many of the other filesystems related to HPSS, it should be monitored for fullness periodically by the administrator.

Configure /opt/hpss as a separate filesystem on the each of the HPSS server and mover nodes. This directory contains the HPSS executables, documentation, libraries, and, for those sites with source code, the development environment to build the HPSS system. For most sites, this filesystem can be configured with 1GB of space. For those sites with source code, at least 2GBs are required.

4.3. Setup Tape Libraries

4.3.1. Special LTO Considerations

When using the LTO PVR, there are special considerations for tape placement.

Storing HPSS and non-HPSS tapes within the same logical library is not recommended. If a non- HPSS application moves tapes around within the library, it can confuse the HPSS PVR about the state of the LTO tape library map (which keeps track of tape locations and available slots). This will cause the map to be re-initialized each time the PVR queries an inconsistent slot, which can cause a significant performance slowdown.

If the logical library must be shared between HPSS and non-HPSS tapes, the following steps should be taken:

•HPSS tapes should be stored in lower numbered slots than the non-HPSS tapes.

•Leave enough empty slots after the HPSS tapes to hold any future HPSS tapes added to this library. The maximum number of HPSS tapes the library may hold is specified in HPSS in the "Cartridge Capacity" field of the Specific Config portion of the LTO PVR server configuration associated with the library.

•Care should be taken so that the non-HPSS applications avoid using slots that have been used for HPSS tapes.

•The tape drive should be locked within HPSS before it is used by a non-HPSS application

If the map becomes inconsistent there may be an occasional error or warning message displayed by the PVR. The message will be similar to: “(d) Invalid parameters passed to LTO Library”. This indicates that the PVR is re-reading the library map. The problem is self correcting and should not require outside intervention, beyond issuing a “Mark Repaired” on the affected servers.

4.3.2. IBM 3584

If using an IBM 3584 tape library, install the Atape driver, configure the SCSI Medium Changer

HPSS Installation Guide	July 2008
Release 6.2 (Revision 2.0)	121