Debian image for QEMU
How to create and run Debian image with QEMU. Might be useful for testing.
Create the hard disk image of ‘qcow2’ format (-f option) with specified filename and 4 gigabytes size:
$ qemu-img create -f qcow2 debian-base.qcow 4G
Download installation .iso from the https://www.debian.org/distrib/. Boot the image with previously created image as hard disk 0 (-hda option), 512 megabytes of RAM (-m option), downloaded .iso as CD-ROM (-cdrom option) and with the first CD-ROM as boot drive (-b option):
$ qemu-system-x86_64 -hda debian-base.qcow -m 512 -cdrom debian-9.8.0-amd64-netinst.iso -boot d
After the installation is done, the system can be booted with (append next options to enable ssh forwarding: -net nic -net user,hostfwd=tcp::2222-:22):
$ qemu-system-x86_64 -hda debian-base.qcow -m 512
Taking a snapshot of ‘qcow2’ format (-f option) using specified file as base image (-b option):
$ qemu-img create -f qcow2 -b debian-base.qcow debian-base-snapshot-01.qcow
Run from the snapshot:
$ qemu-system-x86_64 -hda debian-base-snapshot-01.qcow -m 512
To avoid changing the hard drive image during run add -snapshot option and changes will be written to temporary files leaving disk image unaffected.
Useful links: