Re: [PATCH] Support OpenIndiana in GRUB2

[Seth Goldberg]

Quoting Vladimir 'φ-coder/phcoder' Serbinenko, who wrote the following on...:

> On 08.11.2011 19:16, Seth Goldberg wrote:
> > Quoting Vladimir 'φ-coder/phcoder' Serbinenko, who wrote the following
> > on...:
> >
> > > Resending because of wrong oi-dev address at first try which caused it
> > > to be rejected from other 2 lists as well
> > > On 08.11.2011 02:19, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> > > > With this patch on top of trunk I was able to compile (using
> > > > GCC+GAS+GNU
> > > > LD), install, generate config and boot OpenIndiana. Some areas are grey
> > > > to me. As like:
> > > > 1) Is it better to determine zfs-bootfs parameter on boot or on config.
> >
> > (These opinions are based on Oracle Solaris):
> > Some grub entries may not specify a bootfs, in which case, GRUB should
> > derive it from the bootfs property in the pool
> bootfs is an annoying one since on-disk AFAIK only its objnum is stored
> so we need to scan to determine its name. But for me it's only
> backward-compatibility issue. This property shouldn't be necessary with
> new or autodetected config.

  It's true you can get around it by triggering a config file autogeneration 
when the bootfs property is changed.

> > > > GRUB-Legacy does former but it has the problem that rpool may be
> > > > inaccessible to GRUB (it may be that only /boot/grub is accessible
> > > > to it)
> >
> >   If the rpool is in accessible, then the top-level dataset should
> > also be inaccessible (unless I'm misunderstanding what you mean).
> You can have a small disk locally holding only GRUB2, kernel and boot
> archive and rpool in a SAN, boot_archive taking care of mounting rpool.

  I'm not aware of any OpenSolaris distro doing that, but it is possible.  In 
that case, it's up to the administrator to ensure that the bootfs value used 
is correct and that the pool is accessible to GRUB2.


> > > > 2) What's the best way to handle "local" keyword?
> >
> >   Remove it ;) ?
> I have a patch for it few lines down in this ML.

  LGTM.

> > > > 3) Does Illumos support* multiple kernels?
> >
> > (For O.S.)  This is something that developers would use, IMHO, but not
> > something for production, because the boot environment construct is
> > used to isolate different bootable instances.
> Could you explain better what's boot environment is? Is it separate
> subvolume? How do we discover them. Should it be on runtime or config time?

  A boot environment is a child zfs dataset whose name is of a specific form 
(<poolname>/ROOT/<BEname>).  Each boot environment is a separate, 
fully-contained bootable instance of Solaris.  As of the last OpenSolaris 
release, the only shared state is that state stored on the top-level dataset 
of the root pool (that include the Legacy GRUB menu.lst, boot signature (just 
a file that can be used to identify the pool with findroot()), and some other 
miscellaneous data). (See the beadm(1M) command for a better explanation).

 Thanks,
 --S