Managing Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64), February 2008

Serviceguard Extension for SAP on Linux Cluster Administration
Change Management
Chapter 5 211
Entries in /etc/hosts, /etc/services, /etc/passwd or /etc/group
should be kept unified across all cluster nodes.
If you use an ORACLE database, be aware that the listener
configuration file of SQL*Net V2 is kept as a local copy in
/etc/listener.ora by default.
Files in the following directories and all subdirectories are typically
shared:
/usr/sap/<SID>/DVEBMGS<INR>
/export/usr/sap/trans (except for stand-alone J2EE)
/export/sapmnt/<SID>
Chapter Two can be referenced for a full list of cluster shared directories.
These directories are only available on a cluster node if the package they
belong to is running on it. They are empty on all other nodes. The
Serviceguard package and the directories for this package together
failover to another cluster node.
All directories below /export have an equivalent directory whose fully
qualified path comes without this prefix. These directories are managed
by the automounter. NFS file systems and get mounted automatically as
needed. Servers outside of the cluster that have External Dialog
Instances installed are set up in a similar way. Refer to
/etc/auto.direct for a full list of automounter file systems of
Serviceguard Extension for SAP on Linux.
It enhances the security of the installation if the directories below
/export are exported without root permissions. The effect is, that the root
user cannot modify these directories or their contents. With standard
permissions set, the root user cannot even see the files. If changes need
to be done as the root user, the equivalent directory below /export on the
host the package runs on can be used as access point.
If the Serviceguard Extension for SAP on Linux package (sapnfs) of the
NFS server host is not available it is possible that the logon will hang if
it is attempted as <sid>adm user. The reason for this is, that
/usr/sap/<SID>/SYS/exe is part of the path of the <sid>adm user. This
directory is linked to /sapmnt/<SID> which in fact is handled by the
automounter. If the (sapnfs) package is down the automounter cannot
contact the virtual host of that Serviceguard package (the virtual IP
address is disabled when the package is halted). This is the reason why a
local copy of the SAP executables is kept on each cluster node.