Main architecture of Oracle 11G RAC GRID

CRSD (Cluster ready service daemon)

Management of high-level (applied) resources

OCR

OHASD (Oracle high availability daemon)

Manage low-level resources

OLR (oracle local registry) and GPnP profile are required to start

Started by / etc/init.d/ohasd script, / etc/inittab enabled

GPnP (grid plug and play)

The XML file is saved locally at each node, recording the basic information needed for this node to join the cluster, such as:

Clustername, common network, all networks, asm discovery string (which AU does spfile belong to in asm)

And the files of each node are synchronized by GPnPD.

Location: $GRID_HOME/gpnp/profiles/peer/profile.xml

OLR

Record the metadata of the local node, the local stand-in of OCR

Olr storage location: cat / etc/oracle/olr.loc

GPnP profile and OLR are required for nodes to join the cluster

OCR

CRSD manages the meta-data and wallet of OCR,OCR cluster management resources, which are saved as ASM files in ASM

Ocr storage location: cat / etc/oracle/ocr.loc

External Redundancy:1 ocr

Normal Redundancy:2 ocr

High redundancy:3 ocr

Voting disk

Stored in ASM, record cluster node and each node status, provide node member management and node quarantine fencing

Must be a base number

Specific rules:

External Redundancy:1 voting file

Normal Redundancy:3 copies, at least 3 failure group

High redundancy:5 copies, at least 5 failure group

View voting file:

Crsctl query css votedisk