Re: ZFS support in GRUB

[Tuco <tuco.xyz@gmail.com>]

This is very nice. Right now I'm having some trouble with zpool, but
I'll try to boot from a ZFS root with GRUB as soon as I get the
chance.

On 8/10/10, Robert Millan <rmh@gnu.org> wrote:
> - Only ZFS up to (and including) version 14 is supported.

I just checked, version 14 is in kernel 8.1. Is this the version that
will be used for squeeze?

>   For newer
>   versions, we could make update-grub work with separate /boot with
>   minimal effort (poke me if you think this is needed), but complete
>   support for ZFS in root isn't currently being worked on.  We need
>   help in this area.
>
> - Multi-device arrays are not supported.  If they're RAID1 (mirror),
>   we work around this by selecting the first member and using that for
>   boot later.  For array types where more than one disk is needed, GRUB
>   can't boot.  Using a separate /boot can resolve this, however.
>
> - Gzip compression is not supported.  It can probably be implemented
>   without much effort, given that GRUB already has gzip code (for a
>   different purpose, so the API isn't generic enough, but this can be
>   fixed).  Note that the default in ZFS is no compression, and when
>   compression is enabled the default is LZJB, so this is not a big
>   problem.  Also note that in case you enable gzip compression, a
>   separate /boot is not necessary to work around missing support in
>   GRUB.  Simply create new ZFS filesystems for /boot and /lib/modules
>   inside the same zpool, and adjust compression settings accordingly.
>