Info¶
instar info displays image format information, as a drop-in
replacement for qemu-img info.
# Display image format information (matches qemu-img info output)
instar info image.qcow2
# Discover and display the complete backing file chain
instar info --chain image.qcow2
# Inspect LUKS container with inner format detection
instar info --luks-passphrase 'secret' encrypted.luks
The --chain flag iteratively runs the sandboxed info operation on each image
in the backing chain, validating paths against a security allowlist to prevent
directory traversal attacks. See chain-discovery.md for
the full chain discovery design.
Version compatibility¶
Different qemu-img versions produce slightly different output formats:
- qemu-img 6.0-7.2 (Debian 12 bookworm): No "Child node '/file'" section
- qemu-img 8.0+ (Debian 13 trixie): Includes "Child node '/file'" section
By default, instar detects the installed qemu-img version and emits matching output. This ensures true drop-in replacement compatibility.
To explicitly specify which qemu-img version's output format to use:
# Emit output compatible with qemu-img 7.2 (no Child node section)
instar info --qemu-version 7.2 image.qcow2
# Emit output compatible with qemu-img 10.0 (includes Child node section)
instar info --qemu-version 10.0 image.qcow2
See output-formats.md for detailed documentation on output format profiles.