Using Serviceguard Extension for RAC Version A.11.20 - (August 2011)

of the volume groups is to first shut down the ASM instance and its clients (including all databases
that use ASM based storage) on that node.
The major implications of this behavior include the following:
• Many SGeRAC customers use SGeRAC packages to start and shut down Oracle RAC instances.
In the startup and shutdown sequences, the package scripts activate and deactivate the SLVM
volume groups used by the instance.
• For the ASM environment, it is not appropriate to include SLVM volume group activation and
deactivation in the database instance package control script, since the deactivation may fail.
In the SGeRAC Toolkit that is MNP/Simple Dependency-based, the SLVM volume groups
underlying ASM disk groups are managed instead from the package control script for Oracle
Clusterware.
• When there are multiple RAC databases using ASM to manage their storage in the cluster,
online reconfiguration of SLVM volume groups for one database will impact the others, even
if each database is configured with its own set of ASM disk groups and underlying SLVM
volume groups.
• An SLVM volume group is reconfigured online, using the SLVM SNOR feature. This procedure
requires the volume group to be deactivated on all nodes but one. This in turn requires shutting
down the ASM instance and all client database instances on all nodes but one.
However, note that many storage reconfiguration operations can be confined to the ASM
layer. For example, if a new file has to be created in a disk group, there will be no SLVM
operation required, if the disk group has adequate free space. Adding disks to, and deleting
disks from, ASM disk groups may require SLVM reconfiguration (online disk addition is
discussed in the section).
ASM, that the corresponding logical volume be created at the same time, to avoid the potential
impact of a future online SLVM reconfiguration operation to create the logical volume. Note that,
when adding one or more physical volumes in an SLVM configuration, one can avoid an online
SLVM reconfiguration operation by creating a new volume group for the physical volume(s).
ASM may require Modified Backup/Restore Procedures
Backup/restore procedures for databases stored in ASM must make use of Oracle Recovery
Manager (RMAN), per Oracle documentation. Customers wishing to deploy ASM should ensure
that their backup/restore tools/scripts/procedures are compatible with this ASM requirement.
Installation, Configuration, Support, and Troubleshooting
Oracle ASM is part of the Oracle database server installation (both 10g R2 and 11g R1). No
additional software from HP is required to operate ASM in SGeRAC environment. Information on
how to use the optional MNP/Simple Dependency based SGeRAC Toolkit is separately documented.
Oracle ASM and ASM disk groups may be configured at the time of creating a database or as a
separate step. These tasks are carried out using Oracle database management tools, for example,
the database creation wizard dbca. In either case, ensure that SLVM volume groups and raw
disks/LUs have been prepared and activated prior to ASM disk group configuration or
reconfiguration, as discussed in this section. For SLVM, use the names of raw LVs contained in the
SLVM volume groups when Oracle commands and utilities require the specification of the names
of raw HP-UX devices for storing ASM disk groups.
For troubleshooting, it may be useful to look at subdirectories for database and ASM instances
under $ORACLE_BASE/admin/, where log and trace files for these instances are deposited.
Oracle clusterware deposits log and trace information regarding its management of ASM and
database instances under $ORACLE_HOME/log/<hostname>/racg.
78 Support of Oracle RAC ASM with SGeRAC