If you have traditional spinning (hdd) drives, some applications with high concurrency might require MinIO cluster to be tuned such that to avoid random I/O on the drives. The way to convert high concurrent I/O into a sequential I/O is by reducing the number of concurrent operations allowed per cluster. This allows MinIO cluster to be operationally resilient to such workloads, while also making sure the drives are at optimal efficiency and responsive.

version:
address: ':9000'
console-address: ':9001'
certs-dir: '/home/user/.minio/certs/'
pools: # Specify the nodes and drives with pools
  -
        - 'https://server-example-pool1:9000/mnt/disk{1...4}/'
        - 'https://server1-pool1:9000/mnt/disk{1...4}/'
        - 'https://server3-pool1:9000/mnt/disk{1...4}/'
        - 'https://server4-pool1:9000/mnt/disk{1...4}/'
  -
        - 'https://server-example-pool2:9000/mnt/disk{1...4}/'

func TestErasureHeal(t *testing.T) {
	for i, test := range erasureHealTests {
		if test.offDisks < test.badStaleDisks {
			// test case sanity check
			t.Fatalf("Test %d: Bad test case - number of stale drives cannot be less than number of badstale drives", i)
		}

		// create some test data
		setup, err := newErasureTestSetup(t, test.dataBlocks, test.disks-test.dataBlocks, test.blocksize)
		if err != nil {

		return config.DefaultHelpPostfix(DefaultKVS, key)
	}

	// Help provides help for config values
	Help = config.HelpKVS{
		config.HelpKV{
			Key:         Bitrot,
			Description: `perform bitrot scan on drives when checking objects during scanner` + defaultHelpPostfix(Bitrot),
			Optional:    true,
			Type:        "on|off",
		},
		config.HelpKV{
			Key:         Sleep,

	if t == nil || t.Publisher.NumSubscribers(t.TraceType) == 0 {
		return c.roundtrip(h, req)
	}

	// Following trimming is needed for consistency between outputs with other internode traces.
	local := strings.TrimPrefix(strings.TrimPrefix(t.Local, httpsScheme), httpScheme)
	remote := strings.TrimPrefix(strings.TrimPrefix(t.Remote, httpsScheme), httpScheme)

	start := time.Now()
	body := bytesOrLength(req)

		echo "my content" | /tmp/mc pipe myminio/testbucket/file-$i
	done
}

function perform_test() {
	start_port=$2

	start_minio_3_node 120 $start_port

	echo "Testing Distributed Erasure setup healing of drives"
	echo "Remove the contents of the disks belonging to '${1}' node"

	rm -rf ${WORK_DIR}/${1}/*/

	set -x
	start_minio_3_node 120 $start_port

	check_heal ${1}
	rv=$?
	if [ "$rv" == "1" ]; then

drives.  Therefore, the number of drives you present must be a multiple of one of these numbers.  Each object is written to a single erasure-coding set.

Minio uses the largest possible EC set size which divides into the number of drives given. For example, *18 drives* are configured as *2 sets of 9 drives*, and *24 drives* are configured as *2 sets of 12 drives*.  This is true for scenarios when running MinIO as a standalone erasure coded deployment. In [distributed setup however node (affinity)...

on 16 drive MinIO deployment. If you use eight data and eight parity drives, the file space usage will be approximately twice, i.e. 100 MiB
file will take 200 MiB space. But, if you use ten data and six parity drives, same 100 MiB file takes around 160 MiB. If you use 14 data and
two parity drives, 100 MiB file takes only approximately 114 MiB.

import "context"

const (
	healthDrivesOfflineCount = "drives_offline_count"
	healthDrivesOnlineCount  = "drives_online_count"
	healthDrivesCount        = "drives_count"
)

var (
	healthDrivesOfflineCountMD = NewGaugeMD(healthDrivesOfflineCount,
		"Count of offline drives in the cluster")
	healthDrivesOnlineCountMD = NewGaugeMD(healthDrivesOnlineCount,
		"Count of online drives in the cluster")

minio server --address :9003 /data/tenant3
```

![Example-1](https://github.com/minio/minio/blob/master/docs/screenshots/Example-1.jpg?raw=true)

### 1.2 Host Multiple Tenants on Multiple Drives (Erasure Code)

Use the following commands to host 3 tenants on multiple drives:

```sh
minio server --address :9001 /disk{1...4}/data/tenant1
minio server --address :9002 /disk{1...4}/data/tenant2
minio server --address :9003 /disk{1...4}/data/tenant3
```