OHASD has access to OLR (oracle local
registry). OHASD then reads the OLR content and initialize accordingly.
OHASD brings up GPnP (ora.gpnpd)Daemon and CSS (ora.cssd) Daemon.
CSS Daemon has access to the GPNP Profile stored on the local file system. I even found a copy of GPNP Profile directly stored in OLR (in Oracle 12c release 2)
The Voting Files locations on ASM Disks are accessed by CSSD with well-known pointers in the ASM Disk headers and CSSD is able to complete initialization and start or join an existing cluster.
OHASD starts an ASM instance. The ASM instance uses special code to locate the contents of the ASM SPFILE, if it is stored in a Diskgroup.
With an ASM instance operating and its Diskgroups mounted, access to Clusterware’s OCR is available to CRS.
OHASD then starts CRSD (ora.crsd)damon with access to the OCR in an ASM Diskgroup.
And thus Clusterware completes initialization and brings up other cluster managed resources defined in OCR.
OHASD brings up GPnP (ora.gpnpd)Daemon and CSS (ora.cssd) Daemon.
CSS Daemon has access to the GPNP Profile stored on the local file system. I even found a copy of GPNP Profile directly stored in OLR (in Oracle 12c release 2)
The Voting Files locations on ASM Disks are accessed by CSSD with well-known pointers in the ASM Disk headers and CSSD is able to complete initialization and start or join an existing cluster.
OHASD starts an ASM instance. The ASM instance uses special code to locate the contents of the ASM SPFILE, if it is stored in a Diskgroup.
With an ASM instance operating and its Diskgroups mounted, access to Clusterware’s OCR is available to CRS.
OHASD then starts CRSD (ora.crsd)damon with access to the OCR in an ASM Diskgroup.
And thus Clusterware completes initialization and brings up other cluster managed resources defined in OCR.
Level 1:
OHASD Spawns:
- cssdagent
– Agent responsible for spawning CSSD.
- orarootagent
– Agent responsible for managing all root owned ohasd resources.
- oraagent
– Agent responsible for managing all oracle owned ohasd resources.
- cssdmonitor
– Monitors CSSD and node health (along wth the cssdagent).
Level 2:
OHASD rootagent spawns:
- CRSD
– Primary daemon responsible for managing cluster resources.
- CTSSD
– Cluster Time Synchronization Services Daemon
- Diskmon
- ACFS
(ASM Cluster File System) Drivers
Level 2:
OHASD oraagent spawns:
- MDNSD
– Used for DNS lookup
- GIPCD
– Used for inter-process and inter-node communication
- GPNPD
– Grid Plug & Play Profile Daemon
- EVMD
– Event Monitor Daemon
- ASM
– Resource for monitoring ASM instances
Level 3:
CRSD spawns:
- orarootagent
– Agent responsible for managing all root owned crsd resources.
- oraagent
– Agent responsible for managing all oracle owned crsd resources.
Level 4:
CRSD rootagent spawns:
- Network
resource – To monitor the public network
- SCAN
VIP(s) – Single Client Access Name Virtual IPs
- Node
VIPs – One per node
- ACFS
Registery – For mounting ASM Cluster File System
- GNS
VIP (optional) – VIP for GNS
Level 4:
CRSD oraagent spawns:
- ASM
Resouce – ASM Instance(s) resource
- Diskgroup
– Used for managing/monitoring ASM diskgroups.
- DB
Resource – Used for monitoring and managing the DB and instances
- SCAN
Listener – Listener for single client access name, listening on SCAN VIP
- Listener
– Node listener listening on the Node VIP
- Services
– Used for monitoring and managing services
- ONS
– Oracle Notification Service
- eONS
– Enhanced Oracle Notification Service
- GSD
– For 9i backward compatibility
- GNS
(optional) – Grid Naming Service – Performs name resolution