### Allowed values for STANDARD storage class

`STANDARD` storage class implies more parity than `REDUCED_REDUNDANCY` class. So, `STANDARD` parity drives should be

- Greater than or equal to 2, if `REDUCED_REDUNDANCY` parity is not set.
- Greater than `REDUCED_REDUNDANCY` parity, if it is set.

Parity blocks can not be higher than data blocks, so `STANDARD` storage class parity can not be higher than N/2. (N being total number of drives)

reconstruct missing or corrupted data. MinIO uses Reed-Solomon code to shard objects into variable data and parity blocks. For example, in a 12 drive setup, an object can be sharded to a variable number of data and parity blocks across all the drives - ranging from six data and six parity blocks to ten data and two parity blocks.

By default, MinIO shards the objects across N/2 data and N/2 parity drives. Though, you can use [storage classes](https://github.com/minio/minio/tree/master/docs/erasure/storage-class)...

		t.Fatalf("Unable to format drives for erasure, %s", err)
	}

	ep := PoolEndpoints{Endpoints: endpoints}

	parity, err := ecDrivesNoConfig(16)
	if err != nil {
		t.Fatalf("Unexpected error during EC drive config: %v", err)
	}
	if _, err := newErasureSets(ctx, ep, storageDisks, format, parity, 0); err != nil {
		t.Fatalf("Unable to initialize erasure")
	}
}

		version == xlMetaVersion100) &&
		format == xlMetaFormat)
}

// Verifies if the backend format metadata is sane by validating
// the ErasureInfo, i.e. data and parity blocks.
func isXLMetaErasureInfoValid(data, parity int) bool {
	return ((data >= parity) && (data > 0) && (parity >= 0))
}

//go:generate msgp -file=$GOFILE -unexported

// A xlMetaV1Object represents `xl.meta` metadata header.
type xlMetaV1Object struct {

			Standard: StorageClass{
				Parity: 8,
			},
			RRS: StorageClass{
				Parity: 2,
			},
			initialized: true,
		}
		// Set env var for test case 4
		if i+1 == 4 {
			scfg.RRS.Parity = 7
		}
		// Set env var for test case 5
		if i+1 == 5 {
			scfg.Standard.Parity = 6
		}
		// Set env var for test case 6
		if i+1 == 6 {
			scfg.Standard.Parity = 7
		}

		"Please check the value",
		`MINIO_STORAGE_CLASS_STANDARD: Format "EC:<Default_Parity_Standard_Class>" (e.g. "EC:3"). This sets the number of parity drives for MinIO server in Standard mode. Objects are stored in Standard mode, if storage class is not defined in Put request

# Erasure code sizing guide

## Toy Setups

Capacity constrained environments, MinIO will work but not recommended for production.

| servers | drives (per node) | stripe_size | parity chosen (default) | tolerance for reads (servers) | tolerance for writes (servers) |
|--------:|------------------:|------------:|------------------------:|------------------------------:|-------------------------------:|

	}

	Help = config.HelpKVS{
		config.HelpKV{
			Key:         ClassStandard,
			Description: `set the parity count for default standard storage class` + defaultHelpPostfix(ClassStandard),
			Optional:    true,
			Type:        "string",
		},
		config.HelpKV{
			Key:         ClassRRS,
			Description: `set the parity count for reduced redundancy storage class` + defaultHelpPostfix(ClassRRS),
			Optional:    true,

of common SLA here original cluster had 1024 drives with 16 drives per erasure set with default parity of '4', second pool is expected to have a minimum of 8 drives per erasure set to match the original cluster SLA (parity count) of '4'. '12' drives stripe per erasure set in the second pool satisfies the original pool's parity count.

Refer to the sizing guide with details on the default parity count chosen for different erasure stripe sizes [here](https://github.com/minio/minio/blob/mas...

		if n == 0 && total != 0 {
			// Reached EOF, nothing more to be done.
			break
		}

		// We take care of the situation where if n == 0 and total == 0 by creating empty data and parity files.
		blocks, err = e.EncodeData(ctx, buf[:n])
		if err != nil {
			return 0, err
		}

		if err = writer.Write(ctx, blocks); err != nil {
			return 0, err
		}

		total += int64(n)