Re: Getting a unique ID for a system?
On Thu, Nov 20, 2008 at 02:28, Douglas A. Tutty <firstname.lastname@example.org> wrote:
> What about virtual hosts that may migrate from one piece of hardware to
> another? Wouldn't VMs mean that you need a unique host ID separate from
Yes, that is the point. But a cloned VM would create a duplicate ID. If not
for this, I would have used .etc.hostid, already.
> Why not just assign sequential IDs as new hosts are created, never
> duplicating them? In this sense, all hosts would be virtual, whether
> actually virtual (VMs) or single host on/in a single box.
Because looking up the IDs that are taken is not always feasible. With
uuids, you do not have that problem.
> It could be used as a database key, which links virtual hosts to what
> they are running on. The database could also contain an entry for each
> component that makes up a host (if you wish), e.g. brand-model-serial
> for a case (e.g. what I see in front of me: HP-D6131-60200-US84700448
> [HP NetServer LPr PII/450).
Newer versions of some SQL daemons offer native uuid support. Putting
a description into an ID is an absolute no-go, though. You are thinking
of a name, and I have a scheme for that, namely DNS.
> What you are describing is just part of the larger issue of namespace
> managment. Work out exactly what you want, the criteria not the method.
I know what I want. A db table with proper relations that, amongst others,
tracks all assets. The unique ID for running OSes is the only remaining
thing I miss.