qcow-rs

A Rust library for working with qcow images.

Example

// open qcow
let qcow = qcow::open(PATH).unwrap();

// print out list of snapshots in the qcow
for snapshot in qcow.snapshots() {
    println!(
        "Snapshot {:?}: {:?} (size = {})",
        snapshot.unique_id,
        snapshot.name,
        snapshot.vm_state_size
    );
}

// create a reader for accessing the virtual hard disk
let mut file = BufReader::new(File::open(PATH)?);
let qcow2 = qcow.unwrap_qcow2();
let mut reader = qcow2.reader(&mut file);

// read the first 10 bytes of the virtual hard disk
let mut buf = [0; 10];
reader.read_exact(&mut buf)?;

Features

• Parse qcow files
• Full qcow version 1 support
  • Support for parsing the header and some associated data
• Full qcow version 2-3 support
  • Header parsing, including extra version 3 header data
  • Header extension parsing, allowing you to use addition data they provide
  • Lookup table (L1 and L2) parsing, only loading L2 tables on demand
  • Snapshot parsing, including snapshot L1 lookup tables
  • Support for reading the contents of the virtual disk
    • Includes compression support (for both zlib and zstd)
    • Cluster lookup caching, backtracking on cache miss
    • Allows arbitrary seeking within the guest