Storage Health Monitoring

The BMC continuously monitors system resources including CPU utilization, memory usage, and storage space. When these metrics exceed configured thresholds, warning or critical event logs are automatically generated to alert administrators.

Event logs can be viewed via the Redfish API at /redfish/v1/Systems/system/LogServices/EventLog/Entries.

CPU Metrics

The following table defines the thresholds for CPU utilization alerts:

Metric	Alert Type	Warning	Critical	Action	Description
CPU	Upper	>80%	>95%	Log only	Total BMC CPU utilization
CPU user	Upper	>80%	>95%	Log only	CPU time in user-space applications
CPU kernel	Upper	>80%	>95%	Log only	CPU time in kernel operations

Metric Log Example

To check the current event log for CPU alerts:

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            curl -k -u <usr>:<password> -H 'content-type: application/json' -X GET https://<bmc_ip>/redfish/v1/Systems/Bluefield/LogServices/EventLog/Entries

Example output

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            {
      "@odata.id": "/redfish/v1/Systems/Bluefield/LogServices/EventLog/Entries/468",
      "@odata.type": "#LogEntry.v1_15_0.LogEntry",
      "AdditionalDataURI": "/redfish/v1/Systems/Bluefield/LogServices/EventLog/Entries/468/attachment",
      "Created": "2026-01-19T15:57:22+00:00",
      "EntryType": "Event",
      "Id": "468",
      "Message": "CPU sensor crossed a critical high threshold going high. Reading=96.881238 Threshold=95.000000.",
      "MessageArgs": [
        "CPU",
        "96.881238",
        "95.000000"
      ],
      "MessageId": "OpenBMC.0.4.SensorThresholdCriticalHighGoingHigh",
      "Name": "System Event Log Entry",
      "Resolution": "None",
      "Resolved": false,
      "Severity": "Critical"
}

Memory Metrics

Metric	Alert Type	Warning	Critical	Action	Description
Memory available	Lower	<30%	<10%	Log only	Memory available for applications
Memory shared	Upper	-	>35%	Log only	Shared memory usage

Storage Metrics

The BMC system provides real-time monitoring of read-write (RW) flash usage. You can query free storage space, receive notifications when usage crosses defined thresholds, and rely on automatic cleanup when limits are exceeded.

The following table defines the thresholds for storage usage alerts. Note that percentages refer to used space:

Metric	Alert Type	Warning	Critical	Path	Action	Description
Storage RW	Lower	<10%	<5%	`/run/initramfs/rw`	Auto cleanup	Root overlay filesystem; primary writable storage for BMC runtime data and configuration changes
Storage TMP	Lower	<20%	<5%	`/tmp`	Log only	Temporary files storage; used by services for transient data, cleared on reboot
Storage LOGGING	Lower	<30%	<20%	`/var/lib/logging`	Log only	Event logs and dump storage; contains Redfish logs, SEL entries, and debug dumps

Retrieving Free Storage Space

To check the current free RW flash space:

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            curl -k -H "X-Auth-Token: $token" -X GET https://${bmc}/redfish/v1/Managers/Bluefield_BMC/ManagerDiagnosticData'

Example output:

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            {
  "@odata.id": "/redfish/v1/Managers/Bluefield_BMC/ManagerDiagnosticData",
  "@odata.type": "#ManagerDiagnosticData.v1_2_0.ManagerDiagnosticData",
  "FreeStorageSpaceKiB": 1488,
  "Id": "ManagerDiagnosticData",
  "MemoryStatistics": {
    "AvailableBytes": 725983232,
    "BuffersAndCacheBytes": 170594304,
    "FreeBytes": 605347840,
    "SharedBytes": 60747776,
    "TotalBytes": 917188608
  },
  "Name": "Manager Diagnostic Data",
  "ProcessorStatistics": {
    "KernelPercent": 0.6058,
    "UserPercent": 0.5048
  },
  "ServiceRootUptimeSeconds": 1282378.351
}

Storage Cleanup Notifications

When RW flash usage exceeds 90%, a Redfish event log entry is generated to alert that manual cleanup is required.

Example log:

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            {
  "@odata.id": "/redfish/v1/Systems/Bluefield/LogServices/EventLog/Entries/7",
  "@odata.type": "#LogEntry.v1_15_0.LogEntry",
  "Created": "2025-09-15T13:30:43+00:00",
  "EntryType": "Event",
  "Id": "7",
  "Message": "Processes consuming HIGH Resource Storage_RW are 91%",
  "MessageArgs": [
    "Storage_RW",
    "91%"
  ],
  "MessageId": "OpenBMC.0.4.BMCSystemResourceInfo",
  "Name": "System Event Log Entry",
  "Resolution": "None.",
  "Resolved": false,
  "Severity": "OK"
}

Automatic Cleanup

When RW flash usage exceeds 95%, the BMC automatically purges space by deleting:

All dump files
All event logs
Files in home directories
Files in system log directories

Warning

Exceeding 99% RW flash usage can make BMC functionality unstable and impede automatic cleanup.

After automatic cleanup, a Redfish event log entry is generated. For example:

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            {
  "@odata.id": "/redfish/v1/Systems/Bluefield/LogServices/EventLog/Entries/3",
  "@odata.type": "#LogEntry.v1_15_0.LogEntry",
  "Created": "2025-09-24T10:40:34+00:00",
  "EntryType": "Event",
  "Id": "3",
  "Message": "RWFS cleanup completed.",
  "Modified": "2025-09-22T10:40:34+00:00",
  "Name": "System Event Log Entry",
  "Resolved": false,
      "Severity": "OK"
    }

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