QEMU-IMG(1)QEMU-IMG(1)NAMEqemu-img - QEMU disk image utility
SYNOPSIS
usage: qemu-img command [command options]
OPTIONS
The following commands are supported:
create [-e] [-6] [-b base_image] [-f fmt] filename [size]
commit [-f fmt] filename
convert [-c] [-e] [-6] [-f fmt] [-O output_fmt] [-B output_base_image]
filename [filename2 [...]] output_filename
info [-f fmt] filename
snapshot [-l | -a snapshot | -c snapshot | -d snapshot] filename
Command parameters:
filename
is a disk image filename
base_image
is the read-only disk image which is used as base for a copy on
write image; the copy on write image only stores the modified
data
output_base_image
forces the output image to be created as a copy on write image of
the specified base image; "output_base_image" should have the same
content as the input's base image, however the path, image format,
etc may differ
fmt is the disk image format. It is guessed automatically in most
cases. The following formats are supported:
"raw"
Raw disk image format (default). This format has the advantage
of being simple and easily exportable to all other emulators.
If your file system supports holes (for example in ext2 or ext3
on Linux or NTFS on Windows), then only the written sectors
will reserve space. Use "qemu-img info" to know the real size
used by the image or "ls -ls" on Unix/Linux.
"qcow2"
QEMU image format, the most versatile format. Use it to have
smaller images (useful if your filesystem does not supports
holes, for example on Windows), optional AES encryption, zlib
based compression and support of multiple VM snapshots.
"qcow"
Old QEMU image format. Left for compatibility.
"cow"
User Mode Linux Copy On Write image format. Used to be the only
growable image format in QEMU. It is supported only for
compatibility with previous versions. It does not work on
win32.
"vmdk"
VMware 3 and 4 compatible image format.
"cloop"
Linux Compressed Loop image, useful only to reuse directly
compressed CD-ROM images present for example in the Knoppix CD-
ROMs.
size
is the disk image size in kilobytes. Optional suffixes "M"
(megabyte, 1024 * 1024) and "G" (gigabyte, 1024 * 1024 * 1024) are
supported and any "k" or "K" is ignored.
output_filename
is the destination disk image filename
output_fmt
is the destination format
-c indicates that target image must be compressed (qcow format only)
-e indicates that the target image must be encrypted (qcow format
only)
-6 indicates that the target image must use compatibility level 6
(vmdk format only)
-h with or without a command shows help and lists the supported
formats
Parameters to snapshot subcommand:
snapshot
is the name of the snapshot to create, apply or delete
-a applies a snapshot (revert disk to saved state)
-c creates a snapshot
-d deletes a snapshot
-l lists all snapshots in the given image
Command description:
create [-6] [-e] [-b base_image] [-f fmt] filename [size]
Create the new disk image filename of size size and format fmt.
If base_image is specified, then the image will record only the
differences from base_image. No size needs to be specified in this
case. base_image will never be modified unless you use the "commit"
monitor command.
commit [-f fmt] filename
Commit the changes recorded in filename in its base image.
convert [-c] [-e] [-f fmt] filename [-O output_fmt] output_filename
Convert the disk image filename to disk image output_filename using
format output_fmt. It can be optionally encrypted ("-e" option) or
compressed ("-c" option).
Only the format "qcow" supports encryption or compression. The
compression is read-only. It means that if a compressed sector is
rewritten, then it is rewritten as uncompressed data.
Encryption uses the AES format which is very secure (128 bit keys).
Use a long password (16 characters) to get maximum protection.
Image conversion is also useful to get smaller image when using a
growable format such as "qcow" or "cow": the empty sectors are
detected and suppressed from the destination image.
info [-f fmt] filename
Give information about the disk image filename. Use it in
particular to know the size reserved on disk which can be different
from the displayed size. If VM snapshots are stored in the disk
image, they are displayed too.
snapshot [-l | -a snapshot | -c snapshot | -d snapshot ] filename
List, apply, create or delete snapshots in image filename.
SEE ALSO
The HTML documentation of QEMU for more precise information and Linux
user mode emulator invocation.
AUTHOR
Fabrice Bellard
2013-06-14 QEMU-IMG(1)
