Re: Building ZFS disk images

On Tue, Sep 28, 2021 at 9:48 AM Rodney W. Grimes
<freebsd-rwg@gndrsh.dnsmgr.net> wrote:
>
> > On Mon, Sep 27, 2021 at 1:54 PM Mark Johnston <markj@freebsd.org> wrote:
> > >
> > > On Thu, Aug 05, 2021 at 10:54:19AM -0500, Alan Somers wrote:
> > > > There's this:
> > > > https://openzfs.github.io/openzfs-docs/man/8/zpool-reguid.8.html .  I
> > > > haven't used it myself.
> > >
> > > Would it be useful to have an rc.d script that can run this, probably
> > > just on the root pool?  It could be configured to run only upon the
> > > first boot, like growfs already does.
> >
> > Absolutely!
>
> Ewwwwwwwwww!  :-)
>
> > >
> > > > On Thu, Aug 5, 2021, 9:29 AM David Chisnall <theraven@freebsd.org> wrote:
> > > >
> > > > > On 05/08/2021 13:53, Alan Somers wrote:
> > > > > > I don't know of any way to do it using the official release scripts
> > > > > > either. One problem is that every ZFS pool and file system is supposed
> > > > > > to have a unique GUID.  So any kind of ZFS release builder would need to
>                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > > > > re-guid the pool on first boot.
>
> Isnt the proper place to solve this lack of Unique UUID creation
> in the tool(s) that are creating the zfs pool in the first place.
>
> Fixing it "post boot" seems to be a far to late hack and doesnt
> fix any of the situations where one might import these pools
> between creation and first boot.

No, because you might create a VM image once, then instantiate it
dozens or thousands of times.  The firstboot solution is great because
it lets you reuse the same image file.

>
> > > > >
> > > > > Is there a tool / command to do this?  I've hit this problem in the
> > > > > past: I have multiple FreeBSD VMs that are all created from the same
> > > > > template and if one dies I can't import its zpool into another because
> > > > > they have the same UUID.
> > > > >
> > > > > It doesn't matter for modern deployments where the VM is stateless and
> > > > > reimaged periodically but it's annoying for classic deployments where I
> > > > > have things I care about on the VM.
> > > > >
> > > > > David
> >
> >
>
> --
> Rod Grimes                                                 rgrimes@freebsd.org