You may query the cluster probe endpoint to check if the node which received the request can be taken down for maintenance, if the server replies back '412 Precondition Failed' this means you will lose HA. '200 OK' means you are okay to proceed.

```
curl http://minio1:9001/minio/health/cluster?maintenance=true
HTTP/1.1 412 Precondition Failed
Accept-Ranges: bytes
Content-Length: 0
Server: MinIO
Vary: Origin

MinIO supports two storage classes, Reduced Redundancy class and Standard class. These classes can be defined using environment variables
set before starting MinIO server. After the data and parity drives for each storage class are defined using environment variables,
you can set the storage class of an object via request metadata field `x-amz-storage-class`. MinIO server then honors the storage class by
saving the object in specific number of data and parity drives.

    set-drive-count: 4 # Advanced option, must be used under guidance from MinIO team.
```

### Things to know

- Fields such as `version` and `pools` are mandatory, however all other fields are optional.
- Each pool expects a minimum of 2 nodes per pool, and unique non-repeating hosts for each argument.
- Each pool expects each host in this pool has the same number of drives specified as any other host.

# How to monitor MinIO server with Grafana [![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io)

[Grafana](https://grafana.com/) allows you to query, visualize, alert on and understand your metrics no matter where they are stored. Create, explore, and share dashboards with your team and foster a data driven culture.

## Prerequisites

# Metrics Version 3

In metrics version 3, all metrics are available under the endpoint:

```
/minio/metrics/v3
```

however, a specific path under this is required.

Metrics are organized into groups at paths **relative** to the top-level endpoint above.

## Metrics Request Handling

Each endpoint below can be queried at different intervals as needed via a scrape configuration in Prometheus or a compatible metrics collection tool.

## Community Contribution License
All community contributions in this pull request are licensed to the project maintainers
under the terms of the [Apache 2 license](https://www.apache.org/licenses/LICENSE-2.0). 
By creating this pull request I represent that I have the right to license the 
contributions to the project maintainers under the Apache 2 license.

## Description


## Motivation and Context


## How to test this PR?

This is available only on MinIO as an extension to the NewerNoncurrentVersions feature. The following rule makes it possible to remove older noncurrent versions
of objects under the prefix `user-uploads/` as soon as there are more than `N` noncurrent versions of an object.

```
{
    "Rules": [
        {
            "ID": "Keep only most recent 5 noncurrent versions",
            "Status": "Enabled",
            "Filter": {

connectToMinio() {
	SCHEME=$1
	ATTEMPTS=0
	LIMIT=29 # Allow 30 attempts
	set -e   # fail if we can't read the keys.
	ACCESS=$(cat /config/rootUser)
	SECRET=$(cat /config/rootPassword)
	set +e # The connections to minio are allowed to fail.
	echo "Connecting to MinIO server: $SCHEME://$MINIO_ENDPOINT:$MINIO_PORT"
	MC_COMMAND="${MC} alias set myminio $SCHEME://$MINIO_ENDPOINT:$MINIO_PORT $ACCESS $SECRET"
	$MC_COMMAND
	STATUS=$?

The steps below show how to use this notification target in `namespace` format. The other format is very similar and is omitted for brevity.

### Step 1: Ensure Elasticsearch minimum requirements are met

|      16 |                 2 |          16 |                       4 |                             4 |                              4 |

If one or more drives are offline at the start of a PutObject or NewMultipartUpload operation the object will have additional data
protection bits added automatically to provide the regular safety for these objects up to 50% of the number of drives.