qemu-img KVM create disk image howto

 qemu-img create -f qcow2 isotest.qcow2 10G

The above creates a "qcow2" format image called "isotest.qcow2" that is 10GB in size.

If you want to preallocate all of the space for increased performance do this:

qemu-img create -f qcow2 isotest.qcow2 -o preallocation=full 10G
 

It is controlled with the preallocation=full option, of course by default this is set to off (so not using -o preallocation really silently results in -o preallocation=off).

If you want to resize an image check ths out.

How to create from a template/backing image?

qemu-img create -f qcow2 newimagefile.qcow2 -o backing_file=yourfile.qcow2 10G

newimagefile.qcow2 is the new image you are created

yourfile.qcow2 is the base/template image that it is based off (eg. maybe you installed Windows or Linux to yourfile.qcow2 and you want to start from that point so the combined image will be the difference of the original "backing file" vs the changes you make which are reflected in newimagefile.qcow2 (so don't move or delete the original backing file yourfile.qcow2 or you will lose your data).


Tags:

qemu, img, kvm, disk, howto, qcow, isotest, creates, quot, format, gb,

Latest Articles

  • ssh how to connect using a SOCKS 5 proxy with nc and proxycommand
  • Enable AMDGPU Linux Driver
  • apache symlinks denied even with followsymlinks
  • chown how to change ownership on a symlink
  • how to use ifplugd in Linux to execute a command or script when a NIC cable is unplugged or plugged in
  • dd how to backup and restore disk images including compression with gzip
  • mpv / mplayer with Radeon / AMD GPU Video Card Driver enable VDPAU GPU Accelerated Video Decoding
  • Wordpress Reset Blog User Password from MySQL Using Linux Bash and not PHPMyadmin
  • Ubuntu Linux Mint Debian xorg performance and tear-free tuning for AMD Radeon Based Cards
  • Centos 7 Stopped and Disabled Firewalld and ports still blocked
  • MariaDB / MySQL Reset Root Forgotten Password on Centos 7
  • Centos 7 How to install Mysql/Mariadb
  • PHP 7.2, Apache and Centos 7 How To Install
  • Ubuntu Debian Linux Mint r8169 r8168 Network Driver Problem and Solution
  • Linux 3D Performance benchmarks with glxgears 59-60fps solution
  • How To Install Asterisk 16 17 on Debian Ubuntu Linux
  • Linux Ubuntu Debian Centos How To Make a Bootable Windows 7, 8, 10, 2016, 2019 Server USB from ISO
  • How To Restore Windows MBR Bootsector from Linux using syslinux
  • Linux Ubuntu Cannot Print Large Images
  • Cannot Print PDF Solution and Howto Resize