Server Logging

AIStor Server publishes its server logs to the system console. These logs can include errors, information output, or other information useful during troubleshooting or debugging.

Server logs do not emit for all operations and cannot support audit trail or similar compliance requirements. If you require such a trail, configure and use audit logging instead.

You can read the server logs using any of the following methods:

• Run journalctl -u minio from any host machine.
• Run mc admin logs against the MinIO AIStor deployment.

MinIO AIStor can record API, error, and audit logs directly to disk as compressed JSON files. This complements webhook-based logging for compliance, forensics, and offline analysis. Logs are stored internally and managed automatically by MinIO AIStor.

Configure log recording by setting environment variables before starting MinIO AIStor.

API log recording:

export MINIO_LOG_API_INTERNAL_ENABLE="on"
export MINIO_LOG_API_INTERNAL_DRIVE_LIMIT="1Gi"
export MINIO_LOG_API_INTERNAL_FLUSH_COUNT="10000"
export MINIO_LOG_API_INTERNAL_FLUSH_INTERVAL="1h"

Error log recording:

export MINIO_LOG_ERROR_INTERNAL_ENABLE="on"
export MINIO_LOG_ERROR_INTERNAL_DRIVE_LIMIT="1Gi"
export MINIO_LOG_ERROR_INTERNAL_FLUSH_COUNT="10000"
export MINIO_LOG_ERROR_INTERNAL_FLUSH_INTERVAL="1h"

Audit log recording:

export MINIO_LOG_AUDIT_INTERNAL_ENABLE="on"

When the configured drive limit is reached (for API and error logs), MinIO AIStor automatically removes the oldest log files to make room for new entries.

MinIO AIStor supports publishing logs to a webhook consumer through an HTTP PUT operation, where the body of the request is the log as a JSON document.

You can configure a new HTTP webhook endpoint to which AIStor Server publishes minio server logs using either environment variables or runtime configuration settings:

MINIO_LOGGER_WEBHOOK_ENABLE="on"
MINIO_LOGGER_WEBHOOK_ENDPOINT="https://webhook-1.example.net"
#MINIO_LOGGER_WEBHOOK_AUTH_TOKEN="TOKEN"
#MINIO_LOGGER_WEBHOOK_BATCH_SIZE=10
#MINIO_LOGGER_WEBHOOK_CLIENT_CERT="/opt/minio/webhook/public.crt"
#MINIO_LOGGER_WEBHOOK_CLIENT_KEY="/opt/minio/webhook/private.key"
#MINIO_LOGGER_WEBHOOK_MAX_RETRY=5
#MINIO_LOGGER_WEBHOOK_RETRY_INTERVAL=1
#MINIO_LOGGER_WEBHOOK_PROXY="https://proxy.example.net"
#MINIO_LOGGER_WEBHOOK_TLS_SKIP_VERIFICATION=false
#MINIO_LOGGER_WEBHOOK_HTTP_TIMEOUT=10
#MINIO_LOGGER_WEBHOOK_HTTP_ENCODING="json"

mc admin config set ALIAS logger_webhook        \
   endpoint="https://webhook-1.example.net"     \
#  auth_token="TOKEN"                           \
#  batch_size=10                                \
#  max_retry=5                                  \
#  retry_interval=1                             \
#  client_cert="/opt/minio/webhook/public.crt"  \
#  client_key="/opt/minio/webhook/private.key"  \
#  proxy="https://proxy.example.net"            \
#  tls_skip_verification=false                  \
#  http_timeout=10                              \
#  http_encoding="json"

For options that require specifying a directory path, ensure the minio-user user and group have read, write, and list access to those resources. Where possible use chown and chmod to limit access and ownership to only the minio-user.

Restart MinIO AIStor to apply the new settings.

You can specify multiple webhook loggers by appending a unique identifier to each group of environment variables or settings. For example, MINIO_LOGGER_WEBHOOK_ENDPOINT_PRIMARY or mc admin config set alias logger_webhook:primary.

The following example json document resembles the format used by MinIO AIStor for webhook logging:

{
    "deploymentid": "c8484a3f-2fb0-416b-b0dd-06c7c60a6925",
    "level": "WARNING",
    "time": "2025-08-15T16:06:01.16308316Z",
    "api": {
        "name": "SYSTEM.iam",
        "args": {}
    },
    "error": {
        "message": "Enabling MINIO_IDENTITY_TLS_SKIP_VERIFY is not recommended in a production environment (*errors.errorString)",
        "source": [
            "internal/logger/logger.go:271:logger.LogIf()",
            "cmd/logging.go:29:cmd.iamLogIf()",
            "cmd/iam.go:270:cmd.(*IAMSys).Init()",
            "cmd/server-main.go:1006:cmd.serverMain.func15.1()",
            "cmd/server-main.go:566:cmd.bootstrapTrace()",
            "cmd/server-main.go:1005:cmd.serverMain.func15()"
        ]
    }
}