Oracle Clusterware Startup Sequence - RAC Startup Sequence (OHASD, CSSD, GPNPD & CRSD) - Oracle RAC

Hello Friends, Here with one more topic on. Oracle Clusterware Startup Sequence - RAC Startup Sequence (OHASD, CSSD, GPNPD & CRSD) - Oracle RAC: ========================================================================================= Interview Question? ohasd process to start what it will look? cssd to start what it will look? crsd to start what it will look? gpnp process to start what it will look? Brief me about clusterware start-up sequence? 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(ora.crsd) - Primary daemon responsible for managing cluster resources. CTSSD(ora.ctssd) - Cluster Time Synchronization Services Daemon Diskmon(ora.diskmon) ACFS (ASM Cluster File System) Drivers Level 2: OHASD oraagent spawns: MDNSD(ora.mdnsd) - Used for DNS lookup GIPCD(ora.gipcd) - Used for inter-process and inter-node communication GPNPD(ora.gpnpd) - Grid Plug & Play Profile Daemon EVMD(ora.evmd) - Event Monitor Daemon ASM(ora.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 #RAC #RACDaemons #OracleClustearwareStartupSequence #exadata #oracle #oracledatabase #oracledba #database #databaseperformanceIssue Please do follow me and support me on, Blog: https://mallik034.blogspot.com/ LinkedIn:   / mallikarjun-ramadurg-397a751a   twitter:   / mallik034   instagram:   / mallik034   YouTube:   / @vismotechnologies   Regards, Mallikarjun Ramadurg Mobile: +966 543796525 WhatsApp: +91 9880616848 Blog: https://mallik034.blogspot.com/ LinkedIn:   / mallikarjun-ramadurg-397a751a   twitter:  / mallik034   Instagram:  / mallik034   YouTube:   / @vismotechnologies