qemu-img - used to create, convert and modify images offline by Xen and KVM
syntax
$ qemu-img subcommand [options]
To get help
$ qemu-img -h
To create disk image
$ qemu-img create ubuntu.img 25G
To create qcow2 disk image
$ qemu-img create -f qcow2 -o size=25G ubuntu.img
To create VMDK disk image
$ qemu-img create -f vmdk -o size=20G debian.img
To get Information about disk image
$ qemu-img info ubuntu.img
$ qemu-img info debian.img
$ qemu-img info fedora.img
To shrink disk image
$ qemu-img convert -O qcow2 centos.qcow2 centos_shrink.qcow2
To compress disk image
$ qemu-img convert -O qcow2 -c fedora.qcow2 fedora_compress.qcow2
To check disk image for errors
$ qemu-img check ubuntu.qcow2
$ qemu-img check debian.qcow2
$ qemu-img check centos.qcow2
To increase disk image size
$ qemu-img resize ubuntu.qcow2 +5GB
$ qemu-img resize debian.qcow2 +5GB
To create a new disk image on the file system.
$ qemu-img create -f raw ubuntu.img 25G
$ qemu-img create -f vmdk ubuntu.vmdk 25G
To converts an existing disk image from one format to another
$ qemu-img convert -O qcow2 ubuntu.vmdk ubuntu.qcow2
$ qemu-img convert -O qcow2 debian.vmdk debian.qcow2
To manage snapshots of an existing disk image
$ qemu-img snapshot -c ubuntu_snap1 ubuntu.qcow2
$ qemu-img snapshot -c centos_snap1 centos.qcow2
To list snapshots of VM
$ qemu-img snapshot -l ubuntu.qcow2
$ qemu-img snapshot -l centos.qcow2
To restore the state of the saved snapshot
$ qemu-img snapshot -a 1 ubuntu.qcow2
$ qemu-img snapshot -a 1 centos.qcow2
To delete snapshot
$ qemu-img snapshot -d 1 ubuntu.qcow2
$ qemu-img snapshot -d 1 centos.qcow2
To create a new base image based on an existing disk image
$ qemu-img rebase -b ubuntu.raw ubuntu.qcow2
$ qemu-img rebase -b centos.raw centos.qcow2
regards,
T.Dhanasekar