Can I simply follow the procedure as mentioned here “https://www.virtualmin.com/documentation/system/os/debian-wheezy-to-jessie-distupgrade” or do I have to upgrade to wheezy first and then to jessie?
Each Debian upgrade takes you from one version to the next – you can’t skip a version.
So to go from Debian 6 to 8, you’d first need to perform these steps here:
And once that’s working, you’d then be able to perform the steps in this link:
andreycheck, thank you for your advice =)