On Sat, Nov 7, 2020 at 4:30 PM Benjamin Baier <program...@netzbasis.de> wrote:
> What are the ramifications of a changed UUID?
At the moment, what one gets on OpenBSD depends on whether one uses
dmidecode (on systems where OpenBSD dmidecode actually works -- it doesn't
on some recent systems, even after making the necessary non-default changes
to kern.allowkmem) or sysctl, and sysctl appears to be the outlier.
> What software depends on hw.uuid not changing?
I'm currently looking into alternatives for identifying a machine so that
multiple builds of software (from a common source tree, e.g. via a
shared filesystem) or similar projects can be isolated. The hardware
UUID seems to be a good candidate for part of that, as it is:
1. fairly easy to obtain from several OSes
2. unlikely to change arbitrarily (unlike e.g. hostname)
3. generally available when some other candidates might not be (e.g.
DNS hostname or IP address on a non-networked machine)
4. tied closely to a physical machine (unlike e.g. the hardware MAC
address of a plug-in network interface, which might be installed
in one machine today and a very different machine next year).
I can easily imagine other applications where the uuid should be invariant;
asset tracking is one that springs immediately to mind.
