Managing Serviceguard Extension for SAP Version B.05.10, September 2010

Table 2-3 System and Environment Specific Volume Groups
Device minor
number
VG NamePotential owning
packages
Access PointMount Point
db<SID>
dbci<SID>
jdb<SID>
jdbjci<SID>
sapnfs
shared disk
and HA
NFS
/export/sapmnt/<SID>
db<SID>
dbci<SID>
sapnfs
/export/usr/sap/trans
none
shared disk
/usr/sap/put
The tables can be used to document used device minor numbers. The device minor numbers of
logical volumes need to be identical for each distributed volume group across all cluster nodes.
/usr/sap/<SID> should not be added to a package, because using this as a dynamic mount
point prohibits access to the instance directories of additional SAP application servers that are
locally installed. The /usr/sap/<SID> mount point will also be used to store local SAP
executables. This prevents problems with busy mount points during database package shutdown.
Due to the size of the directory content, it should not be part of the local root file system. The
/usr/sap/tmp might or might not be part of the root file system. This is the working directory
of the operating system collector process saposcol. The size of this directory will rarely be
beyond a few Megabytes.
If you have more than one system, place /usr/sap/put on separate volume groups created on
shared drives. The directory should not be added to any package. This ensures that they are
independent from any SAP WAS system and you can mount them on any host by hand if needed.
All filesystems mounted below /export are part of HA NFS cross-mounting via automounter.
The automounter uses virtual IP addresses to access the HA NFS directories via the path that
comes without the /export prefix. This ensures that the directories are quickly available after
a switchover. The cross-mounting allows coexistence of NFS server and NFS client processes on
nodes within the cluster.
Option 2: SGeSAP NFS Idle Standby Cluster
This option has a simple setup, but it is severely limited in flexibility. In most cases, option 1
should be preferred. A cluster can be configured using option 2 if it fulfills all of the following
prerequisites:
• Only one SGeSAP package is configured in the cluster. Underlying database technology is
a single-instance Oracle RDBMS. The package combines failover services for the database
and all required NFS services and SAP central components (ABAP CI, SCS, ASCS).
Application Server Instances are not installed on cluster nodes. Replicated Enqueue is not
in use.
• Additional SAP software is not installed on the cluster nodes.
The use of a HA NFS service can be configured to export file systems to external Application
Servers that manually mount them. A dedicated NFS package is not possible. Dedicated NFS
requires option 1.
Common Directories that are Kept Local
The following common directories and their files are kept local on each node of the cluster:
26 Planning the Storage Layout