minio/docs/config

MinIO Server Config Guide

Configuration Directory

Till MinIO release RELEASE.2018-08-02T23-11-36Z, MinIO server configuration file (config.json) was stored in the configuration directory specified by --config-dir or defaulted to ${HOME}/.minio. However from releases after RELEASE.2018-08-18T03-49-57Z, the configuration file (only), has been migrated to the storage backend (storage backend is the directory passed to MinIO server while starting the server).

You can specify the location of your existing config using --config-dir, MinIO will migrate the config.json to your backend storage. Your current config.json will be renamed upon successful migration as config.json.deprecated in your current --config-dir. All your existing configurations are honored after this migration.

Additionally --config-dir is now a legacy option which will is scheduled for removal in future, so please update your local startup, ansible scripts accordingly.

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MinIO also encrypts all the config, IAM and policies content with admin credentials.

Certificate Directory

TLS certificates by default are stored under ${HOME}/.minio/certs directory. You need to place certificates here to enable HTTPS based access. Read more about How to secure access to MinIO server with TLS.

Following is the directory structure for MinIO server with TLS certificates.

$ mc tree --files ~/.minio
/home/user1/.minio
└─ certs
   ├─ CAs
   ├─ private.key
   └─ public.crt

You can provide a custom certs directory using --certs-dir command line option.

Credentials

On MinIO admin credentials or root credentials are only allowed to be changed using ENVs namely MINIO_ACCESS_KEY and MINIO_SECRET_KEY. Using the combination of these two values MinIO encrypts the config stored at the backend.

export MINIO_ACCESS_KEY=minio
export MINIO_SECRET_KEY=minio13
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Rotating encryption with new credentials

Additionally if you wish to change the admin credentials, then MinIO will automatically detect this and re-encrypt with new credentials as shown below. For one time only special ENVs as shown below needs to be set for rotating the encryption config.

Old ENVs are never remembered in memory and are destroyed right after they are used to migrate your existing content with new credentials. You are safe to remove them after the server as successfully started, by restarting the services once again.

export MINIO_ACCESS_KEY=newminio
export MINIO_SECRET_KEY=newminio123
export MINIO_ACCESS_KEY_OLD=minio
export MINIO_SECRET_KEY_OLD=minio123
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Once the migration is complete, server will automatically unset the MINIO_ACCESS_KEY_OLD and MINIO_SECRET_KEY_OLD with in the process namespace.

NOTE: Make sure to remove MINIO_ACCESS_KEY_OLD and MINIO_SECRET_KEY_OLD in scripts or service files before next service restarts of the server to avoid double encryption of your existing contents.

Region

KEY:
region  label the location of the server

ARGS:
name     (string)    name of the location of the server e.g. "us-west-rack2"
comment  (sentence)  optionally add a comment to this setting

or environment variables

KEY:
region  label the location of the server

ARGS:
MINIO_REGION_NAME     (string)    name of the location of the server e.g. "us-west-rack2"
MINIO_REGION_COMMENT  (sentence)  optionally add a comment to this setting

Example:

export MINIO_REGION_NAME="my_region"
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Storage Class

By default, parity for objects with standard storage class is set to N/2, and parity for objects with reduced redundancy storage class objects is set to 2. Read more about storage class support in MinIO server here.

KEY:
storage_class  define object level redundancy

ARGS:
standard  (string)    set the parity count for default standard storage class e.g. "EC:4"
rrs       (string)    set the parity count for reduced redundancy storage class e.g. "EC:2"
comment   (sentence)  optionally add a comment to this setting

or environment variables

KEY:
storage_class  define object level redundancy

ARGS:
MINIO_STORAGE_CLASS_STANDARD  (string)    set the parity count for default standard storage class e.g. "EC:4"
MINIO_STORAGE_CLASS_RRS       (string)    set the parity count for reduced redundancy storage class e.g. "EC:2"
MINIO_STORAGE_CLASS_COMMENT   (sentence)  optionally add a comment to this setting

Cache

MinIO provides caching storage tier for primarily gateway deployments, allowing you to cache content for faster reads, cost savings on repeated downloads from the cloud.

KEY:
cache  add caching storage tier

ARGS:
drives*  (csv)       comma separated mountpoints e.g. "/optane1,/optane2"
expiry   (number)    cache expiry duration in days e.g. "90"
quota    (number)    limit cache drive usage in percentage e.g. "90"
exclude  (csv)       comma separated wildcard exclusion patterns e.g. "bucket/*.tmp,*.exe"
after    (number)    minimum number of access before caching an object
comment  (sentence)  optionally add a comment to this setting

or environment variables

KEY:
cache  add caching storage tier

ARGS:
MINIO_CACHE_DRIVES*  (csv)       comma separated mountpoints e.g. "/optane1,/optane2"
MINIO_CACHE_EXPIRY   (number)    cache expiry duration in days e.g. "90"
MINIO_CACHE_QUOTA    (number)    limit cache drive usage in percentage e.g. "90"
MINIO_CACHE_EXCLUDE  (csv)       comma separated wildcard exclusion patterns e.g. "bucket/*.tmp,*.exe"
MINIO_CACHE_AFTER    (number)    minimum number of access before caching an object
MINIO_CACHE_COMMENT  (sentence)  optionally add a comment to this setting

Etcd

MinIO supports storing encrypted IAM assets and bucket DNS records on etcd.

NOTE: if path_prefix is set then MinIO will not federate your buckets, namespaced IAM assets are assumed as isolated tenants, only buckets are considered globally unique but performing a lookup with a bucket which belongs to a different tenant will fail unlike federated setups where MinIO would port-forward and route the request to relevant cluster accordingly. This is a special feature, federated deployments should not need to set path_prefix.

KEY:
etcd  federate multiple clusters for IAM and Bucket DNS

ARGS:
endpoints*       (csv)       comma separated list of etcd endpoints e.g. "http://localhost:2379"
path_prefix      (path)      namespace prefix to isolate tenants e.g. "customer1/"
coredns_path     (path)      shared bucket DNS records, default is "/skydns"
client_cert      (path)      client cert for mTLS authentication
client_cert_key  (path)      client cert key for mTLS authentication
comment          (sentence)  optionally add a comment to this setting

or environment variables

KEY:
etcd  federate multiple clusters for IAM and Bucket DNS

ARGS:
MINIO_ETCD_ENDPOINTS*       (csv)       comma separated list of etcd endpoints e.g. "http://localhost:2379"
MINIO_ETCD_PATH_PREFIX      (path)      namespace prefix to isolate tenants e.g. "customer1/"
MINIO_ETCD_COREDNS_PATH     (path)      shared bucket DNS records, default is "/skydns"
MINIO_ETCD_CLIENT_CERT      (path)      client cert for mTLS authentication
MINIO_ETCD_CLIENT_CERT_KEY  (path)      client cert key for mTLS authentication
MINIO_ETCD_COMMENT          (sentence)  optionally add a comment to this setting

Notifications

Notification targets supported by MinIO are in the following list. To configure individual targets please refer to more detailed documentation here

notify_webhook        publish bucket notifications to webhook endpoints
notify_amqp           publish bucket notifications to AMQP endpoints
notify_kafka          publish bucket notifications to Kafka endpoints
notify_mqtt           publish bucket notifications to MQTT endpoints
notify_nats           publish bucket notifications to NATS endpoints
notify_nsq            publish bucket notifications to NSQ endpoints
notify_mysql          publish bucket notifications to MySQL databases
notify_postgres       publish bucket notifications to Postgres databases
notify_elasticsearch  publish bucket notifications to Elasticsearch endpoints
notify_redis          publish bucket notifications to Redis datastores

Accessing configuration

All configuration changes can be made using mc admin config get/set/reset/export/import commands.

List all config keys available

~ mc admin config set myminio/

Obtain help for each key

~ mc admin config set myminio/ <key>

e.g: mc admin config set myminio/ etcd returns available etcd config args

~ mc admin config set play/ etcd
KEY:
etcd  federate multiple clusters for IAM and Bucket DNS

ARGS:
endpoints*       (csv)       comma separated list of etcd endpoints e.g. "http://localhost:2379"
path_prefix      (path)      namespace prefix to isolate tenants e.g. "customer1/"
coredns_path     (path)      shared bucket DNS records, default is "/skydns"
client_cert      (path)      client cert for mTLS authentication
client_cert_key  (path)      client cert key for mTLS authentication
comment          (sentence)  optionally add a comment to this setting

To get ENV equivalent for each config args use --env flag

~ mc admin config set play/ etcd --env
KEY:
etcd  federate multiple clusters for IAM and Bucket DNS

ARGS:
MINIO_ETCD_ENDPOINTS*       (csv)       comma separated list of etcd endpoints e.g. "http://localhost:2379"
MINIO_ETCD_PATH_PREFIX      (path)      namespace prefix to isolate tenants e.g. "customer1/"
MINIO_ETCD_COREDNS_PATH     (path)      shared bucket DNS records, default is "/skydns"
MINIO_ETCD_CLIENT_CERT      (path)      client cert for mTLS authentication
MINIO_ETCD_CLIENT_CERT_KEY  (path)      client cert key for mTLS authentication
MINIO_ETCD_COMMENT          (sentence)  optionally add a comment to this setting

This behavior is consistent across all keys, each key self documents itself with valid examples.

Environment only settings (not in config)

Usage crawler

Data usage crawler is enabled by default, following ENVs allow for more staggered delay in terms of usage calculation.

The crawler adapts to the system speed and completely pauses when the system is under load. It is possible to adjust the speed of the crawler and thereby the latency of updates being reflected. The delays between each operation of the crawl can be adjusted by the MINIO_DISK_USAGE_CRAWL_DELAY environment variable. By default the value is 10. This means the crawler will sleep 10x the time each operation takes.

This will in most setups make the crawler slow enough to not impact overall system performance. Setting MINIO_DISK_USAGE_CRAWL_DELAY to a lower value will make the crawler faster and setting it to 0 will make the crawler run at full speed (not recommended). Setting it to a higher value will make the crawler slower, further consume less resources.

Example: Following setting will decrease the crawler speed by a factor of 3, reducing the system resource use, but increasing the latency of updates being reflected.

export MINIO_DISK_USAGE_CRAWL_DELAY=30
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Worm (deprecated)

Enable this to turn on Write-Once-Read-Many. By default it is set to off. Set MINIO_WORM=on environment variable to enable WORM mode. This ENV setting is not recommended anymore, please use Object Locking and Object Retention APIs documented here.

Example:

export MINIO_WORM=on
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Browser

Enable or disable access to web UI. By default it is set to on. You may override this field with MINIO_BROWSER environment variable.

Example:

export MINIO_BROWSER=off
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Domain

By default, MinIO supports path-style requests that are of the format http://mydomain.com/bucket/object. MINIO_DOMAIN environment variable is used to enable virtual-host-style requests. If the request Host header matches with (.+).mydomain.com then the matched pattern $1 is used as bucket and the path is used as object. More information on path-style and virtual-host-style here Example:

export MINIO_DOMAIN=mydomain.com
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For advanced use cases MINIO_DOMAIN environment variable supports multiple-domains with comma separated values.

export MINIO_DOMAIN=sub1.mydomain.com,sub2.mydomain.com
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Explore Further

• MinIO Quickstart Guide
• Configure MinIO Server with TLS