qemuio

Documentation

Index

• func Discard(path string, format qemuimg.Format, off, len int64, unmap bool) error
• func Write(path string, format qemuimg.Format, off, len int64, pattern byte) error
• func Zero(path string, format qemuimg.Format, off, len int64) error

Functions

func Discard

func Discard(path string, format qemuimg.Format, off, len int64, unmap bool) error

Discard unmap number of bytes at specified offset. Allocated cluster are deaallocated and replaced with zero clusters.

func Write

func Write(path string, format qemuimg.Format, off, len int64, pattern byte) error

Write writes a number of bytes at a specified offset, allocating all clusters in specified range.

func Zero

func Zero(path string, format qemuimg.Format, off, len int64) error

Zero writes zeros at a specified offset. The behavior depens on qcow2 version; In qcow2 v3, allocate zero clusters, marming entire cluster as zero. In qcow2 v2, if the cluster are unallocated and there is no backing file, do nothing. Otherwise allocate clusters and write actual zeros.