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

## What is Bit Rot protection?

Bit Rot, also known as data rot or silent data corruption is a data loss issue faced by disk drives today. Data on the drive may silently get corrupted without signaling an error has occurred, making bit rot more dangerous than a permanent hard drive failure.

	switch t.tok {
	case '\n':
		t.line++
	case '-':
		if s.Peek() == '>' {
			s.Next()
			t.tok = ARR
			return ARR
		}
	case '@':
		if s.Peek() == '>' {
			s.Next()
			t.tok = ROT
			return ROT
		}
	case '<':
		if s.Peek() == '<' {
			s.Next()
			t.tok = LSH
			return LSH
		}
	case '>':
		if s.Peek() == '>' {
			s.Next()
			t.tok = RSH
			return RSH
		}
	}

type wholeBitrotReader struct {
	disk       StorageAPI
	volume     string
	filePath   string
	verifier   *BitrotVerifier // Holds the bit-rot info
	tillOffset int64           // Affects the length of data requested in disk.ReadFile depending on Read()'s offset
	buf        []byte          // Holds bit-rot verified data
}

func (b *wholeBitrotReader) ReadAt(buf []byte, offset int64) (n int, err error) {
	if b.buf == nil {

						qst, err = bfs.SysBlockDeviceQueueStats(parentDev)
					}
				}
				if err == nil {
					info.NRRequests = qst.NRRequests
					rot := qst.Rotational == 1 // Rotational is '1' if the device is HDD
					info.Rotational = &rot
				}
			}
		}
	}

	return info, nil
}

// GetDriveStats returns IO stats of the drive by its major:minor

// errFileCorrupt - file has an unexpected size, or is not readable
var errFileCorrupt = StorageErr("file is corrupted")

// errBitrotHashAlgoInvalid - the algo for bit-rot hash
// verification is empty or invalid.
var errBitrotHashAlgoInvalid = StorageErr("bit-rot hash algorithm is invalid")

// errCrossDeviceLink - rename across devices not allowed.

	LSH          ScanToken = -1000 - iota // << Left shift.
	RSH                                   // >> Logical right shift.
	ARR                                   // -> Used on ARM for shift type 3, arithmetic right shift.
	ROT                                   // @> Used on ARM for shift type 4, rotate right.
	Include                               // included file started here
	BuildComment                          // //go:build or +build comment

### Data protection