*Answering “NO” here tells the installation script to just go ahead and fully install GRUB2 and not mess with the legacy grub file and fart around with chainloading and stuff.
I just felt better uninstalling a “complete” GRUB2 install rather than a half-assed hodge-podge of grubbery.
Shorewall is designed with the assumption that users will never replace and retaining your existing file will always produce upward-compatible behavior.
That having been said, there are a few settings that you may have in your that will cause compilation warning or error messages after the upgrade.
You could just keep all the kernels you need in , but this would necessitate manual intervention each time Debian made an update to the kernel. pygrub provides a way to furtle around in the root partition of your dom U, fish out the kernel and use it to boot the dom U.
This gives a way of managing Debian stable release upgrades without having to do all the machines in one go.
with 3rd party deb sources and a bunch of custom stuff, your mileage may vary.
I did this to a fresh, new server before anything else.
There is a long tradition of specifying an interface name in the SOURCE column of this file.
Masquerading/SNAT occurs in the Netfilter POSTROUTING chain where an incoming interface may not be specified in iptables rules.
Since the hardware is about a bazillion miles away I don’t know if there’s anything I could have done from the console to fix grub and rescue the install; my only option was the auto re-image in the i Web control panel.