How to permanently change qemu’s qcow2 image?


Of course you heard of qemu. Its a hypervisor used by UNetLab and GNS3 to integrate virtual routers like Alcatel-Lucent’s 7750 SR, Junipers vMX and Cisco’s XRv. And it is well-known that those virtual routers come in the form of qemu disk images with an odd  qcow2 extension. But how can we alter those disc images if we need, for example, preconfigure and distribute an image with some interfaces configured, or got system name changed or even upload a license file?

I invite you to acquire this useful knowledge under the cut section.

ADD: I wrote another post on how to do this stuff automatically with libguestfs tools.