GPNP

The GPnP profile is a small XML file located in GRID_HOME/gpnp/<hostname>/profiles/peer under the name profile.xml. It is used to establish the correct global personality of a node. Each node maintains a local copy of the GPnP Profile and is maintanied by the GPnP Deamon (GPnPD) .

PNP PROFILE CONTAIN  :- 

GPnP Profile  is used to store necessary information required for the startup of Oracle Clusterware like  SPFILE location,ASM DiskString  etc.

It contains various attributes defining node personality.

- Cluster name

- Network classifications (Public/Private)

- Storage to be used for CSS

- Storage to be used for ASM : SPFILE location,ASM DiskString  etc

- Digital signature information : The profile is security sensitive. It might identify the storage to be used as the root partition of a machine.  Hence, it contains digital signature information of the provisioning authority.

WHO UPDATES GPNP PROFILE?

GPnPd daemon replicates changes to the profile during

• - installation,
• - system boot or
• - when updated

Profile is updated Whenever changes are made to a cluster with configuration tools like

• . oifcfg (Change network),
• . crsctl (change location of voting disk),
• . asmcmd (change ASM_DISKSTRING, SPfile location) etc.

HOW IS GPNP PROFILE USED BY CLUSTERWARE?

To start clusterware, voting disk needs to be accessed. If voting disk is on ASM, this information (that voting disk is on ASM) is read from GPnP profile (<orcl:CSS-Profile id=”css” DiscoveryString=”+asm” LeaseDuration=”400″/>).   The voting disk is read using kfed utility  even if ASM is not up.

Next,  the clusterware checks if all the nodes have the updated GPnP profile and the node joins the cluster based on the GPnP configuration . Whenver a node is started/added to the cluster, the clusterware software on the starting node starts a GPnP agent.

• - If the node is already part of the cluster, the GPnP agent reads the existing profile on that node.
• - If the node is being added to the cluster, GPnP agent locates agent on another existing node using multicast protocol (provided by mDNS) and gets the profile from that agent.

Next CRSD needs to read OCR to startup various resources on the node and hence update it as status of resources changes. Since OCR is also on ASM, location of ASM SPfile should be known.

The order of searching the ASM SPfile is

• - GPnP profile
• - ORACLE_HOME/dbs/spfile<sid.ora>
• - ORACLE_HOME/dbs/init<sid.ora>