Mounting from zfs:zroot/ROOT/default failed with error 2 (and 6)

[John Kennedy]

First off, subject change.  I've become convinced that what I'm seeing is two
error messages being mashed together:

[Normal RPI3B+ kernel output
	...
	CPU  0: ARM Cortex-A53 r0p4 affinity:  0
	 Instruction Set Attributes 0 = <CRC32>
	 Instruction Set Attributes 1 = <0>
	...

... and the messages + error:
	Trying to mount root from zfs:zrasp/ROOT/default []...
	Mounting from zfs:zroot/ROOT/default failed with error 2

Digging out that error gets a lot more hits, although typically years old.

As I said, if I comment out zfs_enable="YES" and zfs_load="YES" and boot into
My UFS partition, I can see that the extra modules that get loaded using ZFS
are zfs.ko and opensolaris.ko, even though there are other dependencies:

    [strings -a < opensolaris.ko | grep _depend_on_]
	_opensolaris_depend_on_kernel

    [strings -a < zfs.ko | grep _depend_on_]
	_zfsctrl_depend_on_acl_nfs4
	_zfsctrl_depend_on_kernel
	_zfsctrl_depend_on_krpc
	_zfsctrl_depend_on_opensolaris
	_zfs_depend_on_kernel
	_zfs_zvol_depend_on_kernel
	_zfs_vdev_depend_on_kernel

If I add opensolaris, sort of progress.

	Root mount waiting for: usbus0
	Mounting from zfs:zroot/ROOT/default failed with error 6; retrying for 3 more seconds
	Mounting from zfs:zroot/ROOT/default failed with error 6

Not only that, it looks like it gets me in a non-writing mode:

	ZFS WARNING: Unable to open diskid/DISK-73180AA8s2 for writing (error=1).

Adding in these two didn't seem to make any difference at all (didn't see a load *.ko message):
	acl_nfs4_load="YES"
	krpc_load="YES"

For what it's worth:
    [usbconfig list]
	ugen0.1: <DWCOTG OTG Root HUB> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA)
	ugen0.2: <vendor 0x0424 product 0x2514> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (2mA)
	ugen0.3: <vendor 0x0424 product 0x2514> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (2mA)
	ugen0.4: <vendor 0x0424 product 0x7800> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (2mA)
	ugen0.5: <Logitech USB Receiver> at usbus0, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON (98mA)

<vendor 0x0424 product 0x2514> -> Standard Microsystems Corp. USB 2.0 Hub?

That's presumably my entire BSD space, including UFS which hangs booting (well,
I waited over 10 minutes stayed at "Tryint to mount root" message).  If I power
cycle, interrupt the loader, unload everything and just load the kernel I can
get into the UFS partition just fine from the mountroot> prompt.

If I start up with "boot -v", I see some new messages:

	GEOM_PART: partition 1 on (mmcsd0, MBR) is not aligned to 4194304 bytes
	GEOM_PART: partition 1 on (diskid/DISK-73180AAB, MBR) is not aligned to 4194304 bytes

Those alternate about 5 times inbetween the second-by-second "error 6" countdown.

I'm going to rebuild it with that partition aligned and see what happens.