Features/QED

From QEMU

Contents

Overview

QED is an image format (like qcow2, vmdk, etc) that supports backing files and sparse images.

Status

  • Base QED is in qemu.git since 2010-12-17 and will form part of QEMU 0.14.
  • Merge plan for additional features:
    • Zero clusters [submitted].
    • Periodic dirty flag flush [submitted].
    • Image streaming [in preparation].

Features

  • Open specification
  • Fully asynchronous I/O path
  • Strong data integrity due to simple design
  • Backing files
    • Backing files may be smaller than the QED image
  • Sparse files
    • Retains sparseness over non-sparse channels (e.g. HTTP)

Current work

Future Features