// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package drive

import (
	"sync"
	"time"

	"github.com/minio/minio/internal/config"
	"github.com/minio/pkg/v2/env"
)

// DefaultKVS - default KVS for drive
var DefaultKVS = config.KVS{
	config.KV{
		Key:   MaxTimeout,
		Value: "",
	},
}

var configLk sync.RWMutex

}

func (m *MetricValues) setDriveBasicMetrics(drive madmin.Disk, labels []string) {
	m.Set(driveUsedBytes, float64(drive.UsedSpace), labels...)
	m.Set(driveFreeBytes, float64(drive.AvailableSpace), labels...)
	m.Set(driveTotalBytes, float64(drive.TotalSpace), labels...)
	m.Set(driveUsedInodes, float64(drive.UsedInodes), labels...)
	m.Set(driveFreeInodes, float64(drive.FreeInodes), labels...)

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)...

| `minio_system_drive_used_inodes`               | `gauge`   | Total used inodes on a drive                                       | `drive,set_index,drive_index,pool_index,server`     |
| `minio_system_drive_free_inodes`               | `gauge`   | Total free inodes on a drive                                       | `drive,set_index,drive_index,pool_index,server`     |

var errDriveIsRoot = StorageErr("drive is part of root drive, will not be used")

// errFaultyRemoteDisk - remote disk is faulty.
var errFaultyRemoteDisk = StorageErr("remote drive is faulty")

// errFaultyDisk - disk is faulty.
var errFaultyDisk = StorageErr("drive is faulty")

// errDiskAccessDenied - we don't have write permissions on disk.
var errDiskAccessDenied = StorageErr("drive access denied")

| `minio_node_drive_total_inodes`      | Total inodes on a drive.                                 |
| `minio_node_drive_used_inodes`       | Total inodes used on a drive.                            |
| `minio_node_drive_reads_per_sec`     | Reads per second on a drive.                             |
| `minio_node_drive_reads_kb_per_sec`  | Kilobytes read per second on a drive.                    |

two parity drives, 100 MiB file takes only approximately 114 MiB.

Below is a list of data/parity drives and corresponding _approximate_ storage space usage on a 16 drive MinIO deployment. The field _storage
usage ratio_ is simply the drive space used by the file after erasure-encoding, divided by actual file size.

| Total Drives (N) | Data Drives (D) | Parity Drives (P) | Storage Usage Ratio |

			return fmt.Errorf("%s drive is already being used in another erasure deployment. (Number of drives specified: %d but the number of drives found in the %s drive's format.json: %d)",
				disks[i], len(formats), humanize.Ordinal(i+1), len(formatErasure.Erasure.Sets)*len(formatErasure.Erasure.Sets[0]))
		}
		if len(formatErasure.Erasure.Sets[0]) != setDriveCount {

          "expr": "minio_node_drive_used_bytes{job=~\"$scrape_jobs\",server=\"$server\"}",
          "interval": "",
          "legendFormat": "Used [{{drive}}]",
          "refId": "B"
        },
        {
          "datasource": {
            "type": "prometheus",
            "uid": "${DS_PROMETHEUS}"
          },
          "exemplar": true,

		readsPerSec:       "Reads per second on a drive",
		writesPerSec:      "Writes per second on a drive",
		readsKBPerSec:     "Kilobytes read per second on a drive",
		writesKBPerSec:    "Kilobytes written per second on a drive",
		readsAwait:        "Average time for read requests to be served on a drive",
		writesAwait:       "Average time for write requests to be served on a drive",