Re: difficulties replacing a ZFS installer zroot pool with a new zroot pool on a new disk

On Thu, Mar 31, 2022 at 1:24 AM Russell L. Carter wrote:
>
> On 3/30/22 16:09, Tomasz CEDRO wrote:
> > On Thu, Mar 31, 2022 at 12:48 AM Russell L. Carter wrote:
> >> I installed the new NVMe SSD drive and I was able to boot the USB
> >> install image and install a new FreeBSD system on it.  On reboot I
> >> first tried keeping the old SATA drive as it was.  However the
> >> motherboard BIOS (CSM enabled, legacy, ASUS Prime X570-PRO) refused
> >> all of my efforts to set the boot drive to the new SSD.  I finally
> >> resorted to disconnecting the data cable of the old SATA drive, and
> >> the new SSD booted fine.  I then powered down the motherboard,
> >> reattached the old SATA data cable, and booted.  The motherboard again
> >> refused to boot the new NVMe SSD.  After about an hour of fighting the
> >> BIOS, I gave up, set the SATA drive as "hot pluggable" in the BIOS,
> >> and rebooted with the SATA data cable disconnected.  Once the NVMe SSD
> >> was booted, I reattached the SATA data cable and it showed up in the
> >> 'zpool import' list.  'zpool import zroot' was not a happy solution as
> >> it collided with the new SSD zroot pool.
> >>
> >> I eventually worked out that I should rename the old pool zroot.old on
> >> import.  That was also not a happy solution as it continued to
> >> automatically mount itself on top of the new SSD zroot pool.  I then
> >> worked out that I need to specify an altroot:
> >
> > * I had a similar situation.
> > * I exported old pool and disconnected all old disks.
> > * I have connected only nvm disk and did clean install on it using
> > `znvd` in place of `zroot`.
> > * When new install on a new disk was working fine, power off, connect
> > old disks, import `zroot`, change mountpoint with `zfs set
> > mountpoint=/zroot/something zroot/something`.
> >
> > * Remember not to use different pools with the same name (i.e. `zroot`).
> > * You can also rename pool of the old disks and name new disk pool to
> > zroot to avoid boot problems.
> > * You can use shell from installer drive to manipulate pools easily as
> > the are not /.
> >
> > Hope that helps :-)
> >
>
> Yeah, the crux of the matter is getting those pools named differently.
> I did not notice how to get the new pool renamed during the install,
> must be in the partition menu?  I am not afraid of the 'for experts'
> option but tend to use guided just to be standard.  And I haven't had
> to fight a BIOS like this instance in a very long time.  It's a new
> motherboard, new problems, life goes on.
>
> I am also going to examine carefully what I can do
> when dropping to the shell at the end of the install, as you and
> David Christensen suggest.

You also have LiveCD option aside to Install on the installer boot
media. Do not start Install just go to LiveCD and play a bit over
there.. it comes very handy when something goes wrong you can boot off
the "external" working OS and play with the data on your machine..
also always make a backup before you experiment :-)

-- 
CeDeROM, SQ7MHZ, http://www.tomek.cedro.info