User's Guide

Table 2-3 System and Environment Specific Volume Groups
Device minor
number
VG NamePotential owning packagesAccess 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
noneshared 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, since using this as a dynamic mount point would
prohibit access to the instance directories of locally installed additional SAP application servers. 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). There are no Application Server
Instances installed on cluster nodes. Replicated Enqueue is not in use.
• There is no additional SAP software 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:
• /home/<SID>adm — the home directory of the SAP system administrator with node specific startup
log files
• /usr/sap/<SID>/SYS/exe/run — the directory that holds a local copy of all SAP instance
executables, libraries and tools (optional for kernel 7.x and higher)
• /usr/sap/tmp — the directory in which the SAP operating system collector keeps monitoring data
of the local operating system
• /usr/sap/hostctrl — the directory in which SAP control services for the local host are kept (kernel
7.x and higher)
24 Planning the Storage Layout