Re: Seeing the dreaded "ZFS: i/o error - all block copies unavailable" on 9.0-CURRENT

On Wed, Feb 17, 2010 at 7:49 PM, Chris <behrnetworks_at_gmail.com> wrote:

> As a follow-up to this, I rebuilt world and kernel and updated my
> system to the latest 8.0-STABLE. I'm still seeing the problem and I
> can still get around it by choosing my hard drive from the F12 boot
> menu. I did notice that the bootloader now says it's ZFS enabled
> whereas it didn't while on 8.0-RELEASE. I also updated the bootcode
> with: "gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 adX"
> after installing world. No help there.
>
> It seems to me that there's a difference in the way the ZFS-enabled
> bootloader sees the drives that the BIOS reports as opposed to the
> non-ZFS-enabled bootloader.  Anyone have any ideas on that? I checked
> for any BIOS updates but it looks like I'm current. It sure would be
> nice to not have to select my hard drive each time.
>

Can you paste the exact error? Are you getting something like:

    error 1: lba 32
    error 1: lba 1

When I've seen the above sequence, it was due to a stack overflow (IIRC),
with the result that the loader would start a second time and barf out these
errors.

The "large number" in the error might give us a clue as to what's going on.
If the number is really large, it might be an indication that your BIOS
doesn't reliably read past a certain threshold. ZFS writes a sort of label
at the beginning and end of its drives; perhaps the loader is trying to read
the label at the end of the disk and is failing (I don't recall whether it
tries to read both labels).

Matt