HP Serviceguard Extension for RAC (SGeRAC) manual Background

Clusterware voting and registry devices can also be configured using oracle ASM (Automatic Storage Management) disk groups. The members of disk groups are configured as raw devices (on HP-UX 11i v3). Oracle 11gR2 is supported only on HP-UX 11i v3 (11.31) with SGeRAC A.11.19 or later.

•The RAC database files can be configured as shared raw logical volumes managed by SGeRAC using SLVM or CVM. Beginning with SGeRAC A.11.17, the RAC database files may be configured as shared files managed by SGeRAC using CFS. Also, beginning with Oracle 10g R2 and SGeRAC A.11.17, the RAC database files may also be configured as files in Oracle ASM (Automatic Storage Management) Disk Groups. The members of the ASM Disk Groups are configured as raw devices.

The responsibilities of Oracle Clusterware in this combined environment include the following:

•Management of the database and associated resources (database instances, services, virtual IP addresses (VIPs), listeners, etc.).

•Management of Oracle ASM instances, if configured.

All pieces of the combined stack must start up and shut down in the proper sequence and we need to be able to automate the startup and shutdown sequences, if desired. In particular, the storage needed for the operation of Oracle Clusterware must be activated up before the Oracle Clusterware processes are started, and the storage needed for the operation of a RAC database instance must be activated before the instance is started. On shutdown, the sequence is reversed—Oracle Clusterware and the RAC database instance must be halted before deactivating the storage needed by these two entities.

Traditionally, in the SG and SGeRAC environment, these ordering requirements have been met using a package to encapsulate the startup and shutdown of an application as well as the startup and shutdown of storage needed by that application. In SG and SGeRAC, a different model is introduced for the case where the storage needs of an application are met by using a CFS. Here the CFS is started up and shutdown in a separate package from the one that starts up and shuts down the application. Beginning with patches PHSS_40885/PHSS_40886 SGeRAC has introduced new MNP in to existing SGeRAC toolkit namely ASMDG MNP. In SGeRAC, a different model is recommended for the case where the storage needs of an application are met by using Oracle ASM. Here ASM disk groups are mounted, dismounted, and monitored using a separate MNP package. It also activates and deactivates the shared volume groups needed by the ASM disk groups if ASM is configured over SLVM. The ordering requirement is met by using the SGeRAC feature of simple package dependencies, discussed later in this chapter.

Can we manage the storage needs of Oracle Clusterware and RAC database instances in Oracle RAC, using SGeRAC packages in the ways just discussed? Starting in Oracle 10.1.0.4, Oracle made the following improvements in coordination between Oracle Clusterware and platform clusterware, enabling such use of SGeRAC packages.

Support for on-demand startup and shutdown of Oracle Clusterware and RAC database instances

•In addition to starting up and shutting down Oracle Clusterware automatically as HP-UX 11i is taken up to init level 3 and taken down to a lower level respectively, Oracle Clusterware can be start up and shut down on demand.

•To disable the automatic startup of Oracle Clusterware on entering init level 3, we use the crsctl disable crs command. Oracle Clusterware may thereafter be started up and shut down on demand using the commands crsctl start crs and crsctl stop crs respectively.

•In addition to starting up and shutting down the RAC database instance automatically as Oracle Clusterware itself is started up and shut down, we can start up and shut down the RAC database instance on demand.

•To disable the automatic startup of the RAC database instance with the startup of Oracle Clusterware, we follow the procedures described by Oracle to remove auto-start for the instance. The RAC database instance may thereafter be started up and shut down on demand

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