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.

I would continue to argue that the place to fix this is in the
"instantiate tool".  ESXI vmfs deals with this all the time
when you clone a disk.  And again the "fix at boot" does not
deal with the problem in that if I "instatiate" 10 copies of
a zpool for VM's and then try to mount 2 of them at once on
the host this problem rares it head.   Fix the problem as close
to point of creation as possible for minimal issues in all
operations for everyone.

> 
> >
> > > > > >
> > > > > > 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
> 

-- 
Rod Grimes                                                 rgrimes@freebsd.org