EarIier I wrote about some ways to modify VM disk images used by Unetlab. Basically it boils down to running a VM, console to it and change things through its shell. Obviously, this approach is no way near a handy way to do small changes like:
- loading basic config
- adding license files
In this post I will talk about
guestfish utility which is a part of
libguestfs tools set. With
guestfish one could easily get a shell-like access to the filesystem located on a disk image (qcow2, vmdk, iso and many others). That is how authors of
libguestfs tools describe it:
libguestfs is a set of tools for accessing and modifying virtual machine (VM) disk images
. You can use this for viewing and editing files inside guests, scripting changes to VMs, monitoring disk used/free statistics
, creating guests
, P2V, V2V
, performing backups, cloning VMs, building VMs, formatting disks, resizing disks, and much more.
libguestfs can access almost any disk image imaginable. It can do it securely — without needing root and with multiple layers of defence against rogue disk images. It can access disk images on remote machines or on CDs/USB sticks. It can access proprietary systems like VMware and Hyper-V.
To demonstrate the way how guestfish works I will solve a particular task of adding a license file to Nokia (Alcatel-Lucent) 7750 Virtual Service Router (VSR) by embedding it to the disk image itself. Tune in!
I advertised to you recently another great virtual lab environment – Unified Networking Lab – with tools like that one I practiced the cool technologies of Alcatel-Lucent Service Routing platform and prepared to many certification exams. And I encourage you to go the same way, not just read the books and force the dumps, but actually build a topology and walk through interesting scenarios.
If you boot a Cisco router like 7210 one, or even Juniper vMX, you could configure some interfaces, protocols and so on right away. With Alcatel-Lucent 7750 SR this approach doomed to fail, you should know how bring to life 7750 virtual Service Router (vSR) once you booted it before any further configuration steps.
And this short post will be just about that, what should you configure on 7750 SR after the first boot to make it running with Unetlab or GNS3?