Comparing CHM and SHM: Understanding their fundamental differences

This topic outlines the purpose and usage of Cluster Health Monitor (CHM) and System Health Monitor (SHM).

Cluster Health Monitor (CHM)	System Health Monitor (SHM)
Known as system monitor daemon ( `osysmond` ) is a real-time monitoring and operating system metric collection daemon that runs on each cluster node on RAC systems.	known as system Health Monitor ( `ahf-sysmon` ) is a real time monitoring and operating system collection service available on Single-Instance Database and non-GI based systems.
Integrated and enabled by default as part of GI since 11.2.	Integrated and enabled by default as part of AHF 24.6
Runs as system monitor service ( `osysmond` ) from GI home.	Runs as `ahf-sysmon` service from AHF home.
Managed as High Availability Services (HAS) resource within GI stack.	Managed as `tfa-monitor` resource within AHF stack.
Status of the resource can be queried using below command: `crsctl stat res ora.crf -init -d`	Status of the process can be queried using below command: `ahfctl statusahf`
Generated operating system metrics gets stored in `ORACLE_BASE/crsdata/<hostname>/crf/db/json` Metric Repository is auto-managed on the above local filesystem. Nodeview samples are continuously written to the repository (JSON record) Historical data is auto-archived into hourly zip files Archived files are automatically purged once the default retention limit is reached (default: 200 MB)	Generated operating system metrics gets stored in `/opt/oracle.ahf/data/<hostname>/shm` Metric Repository is auto-managed on the above local filesystem. Metric samples are continuously written to the repository (JSON record) Historical data is auto-archived into hourly zip files Archived files are automatically purged once the default retention limit is reached (default: 200 MB)
Above generated operating system metrics are collected as part `tfactl diagcollect` .	Above generated operating system metrics are collected as part `tfactl diagcollect` .
Supported on Linux, Solaris, AIX, zLinux, ARM64, and Microsoft Windows platforms.	Supported only on Linux platform.