[systemd-devel] hostnamectl question

[Mantas Mikulėnas]

On Tue, Jun 17, 2014 at 8:46 AM, Vasiliy Tolstov <v.tolstov at selfip.ru> wrote:
> I have a problem with uuid on my servers - they all blade servers and
> uuid in smbios identical.
> But i need random uniq id for each system. I can't relay on mac
> address os something like this.
> AS i see systemd have machine id and boot id. And in diskless systems
> they regenerated every boot.
> What is the difference of boot id and machined id ?

Boot ID is *always* generated by the kernel on every boot and not
stored anywhere, only available from sysctl.

Machine ID is usually static -- generated once after installation, and
stored in /etc/machine-id. It only changes on diskless systems or if
/etc is unwritable for some other reason. (systemd can get the machine
ID from /sys/class/dmi/id/product_uuid, but only does so on qemu-kvm
VMs.)

-- 
Mantas Mikulėnas <grawity at gmail.com>