Recovering a zfs root pool from backup

[Karli Sjöberg]

sön 2015-11-22 klockan 15:05 -0800 skrev Chris Stankevitz:
> On 11/22/15 12:32 AM, Karli Sjöberg wrote:
> >  > 1. I doubt I can create a new pool called "zroot" on Machine B since it
> >  > is already running a pool called "zroot"
> >  >
> >  > 2. I doubt that this process will create the appropriate "boot sector"
> >  > stuff (I do not know what I am talking about here).
> >
> > Exactly. You'd need to boot the machine from CD/USB to be able to
> > receive the stream. About the boot stuff. That would need to be handled
> > when partitioning the new drive:
> > # gpart create -t gpt (a)?da[0-9]+
> > # gpart add -t freebsd-boot -s 64k -l boot0 (a)?da[0-9]+
> > # gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 (a)?da[0-9]+
> > # gpart add -t freebsd-swap -b 2048 -s xg -l swap0 (a)?da[0-9]+
> > # gpart add -t freebsd-zfs -a 4k -l sys0 (a)?da[0-9]+
> > # sysctl vfs.zfs.min_auto_ashift=12
> >
> > Also you need to set the "bootfs" property after the receive:
> > # zpool set bootfs=zroot zroot
> 
> Karli,
> 
> Thank you.  Should I be concerned that I cannot "zpool create zroot" 
> from my recovery setup because there will already be a pool with that name?

You´re still thinking of doing the restore process from "Machine B".
Drop that and do it from "Machine A" instead. Just make sure that you
boot "Machine A" from CD/USB. Then there will be no pool called
"zroot":)

/K

> 
> If so, how should I get around that?  I know I can give it a temporarily 
> different name and later export/import to rename it -- but it's not 
> clear to me that I will ever get that renamed given that I will always 
> be running FreeBSD with a zroot.
> 
> Perhaps I could give it a different name "zroot2" (and "zpool set 
> bootfs=zroot2 zroot2")... boot to that... then rename it back to zroot 
> and reboot to complete the restore.
> 
> Thank you again,
> 
> Chris