Managing Serviceguard Extension for SAP, December 2007

Planning the Storage Layout
Database Instance Storage Considerations
Chapter 2 73
NOTE The [Globals] section is commonly shared between LC1/LC2 and
AP1/AP2. This prevents setups that keep the directories of LC1 and AP1
completely separated.
The following directories are of special interest:
• /sapdb/programs: this can be seen as a central directory with all
MAXDB executables. The directory is shared between all MAXDB
instances that reside on the same host. It is also possible to share the
directory across hosts. But it is not possible to use different
executable directories for two MAXDB instances on the same host.
Furthermore, it might happen that different SAPDB versions get
installed on the same host. The files in /sapdb/programs have to be
of the newest version that any MAXDB on the cluster nodes has.
Files in /sapdb/programs are downwards compatible. For liveCache
7.4 and APO 3.1 using SAPDB 7.3 this means that within
/sapdb/programs there have to be the SAPDB 7.4 version
executables installed. It is important to realize, that also any SAPDB
based SAP application server instance will use this path to access the
database client files.
• /sapdb/data/config: This directory is also shared between
instances, though you can find lots of files that are Instance specific
in here, e.g. /sapdb/data/config/<DBSID>.* According to SAP this
path setting is static.
• /sapdb/data/wrk: The working directory of the main MAXDB
processes is also a subdirectory of the IndepData path for non-HA
setups. If a SAPDB restarts after a crash, it copies important files
from this directory to a backup location. This information is then
used to determine the reason of the crash. In HA scenarios, for
SAPDB/MAXDB lower that version 7.6, this directory should move
with the package. Therefore, SAP provided a way to redefine this
path for each SAPBDB/MAXDB individually. SGeSAP expects the
work directory to be part of the database package. The mount point
moves from /sapdb/data/wrk to /sapdb/data/<DBSID>/wrk for the
clustered setup. This directory should not be mixed up with the
directory /sapdb/data/<DBSID>/db/wrk that might also exist. Core
files of the kernel processes are written into the working directory.