Date: Thu, 12 Jul 2012 13:22:08 -0400 From: Kurt Lidl <lidl@pix.net> To: Gavin Mu <gavin.mu@gmail.com> Cc: freebsd-sparc64@freebsd.org, Marius Strobl <marius@alchemy.franken.de> Subject: Re: zfs booting feedback Message-ID: <20120712172208.GA47484@pix.net> In-Reply-To: <CAGEduPJ%2BKpEacYuPVfUV%2BMXRM%2By1-j8k1Gb2wA7MYJ3s71vuBw@mail.gmail.com> References: <20120708025435.GA12487@pix.net> <20120709140019.GA67276@alchemy.franken.de> <20120710165433.GA98707@pix.net> <CAGEduPJ%2BKpEacYuPVfUV%2BMXRM%2By1-j8k1Gb2wA7MYJ3s71vuBw@mail.gmail.com>
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On Thu, Jul 12, 2012 at 03:02:56PM +0800, Gavin Mu wrote:
> On Wed, Jul 11, 2012 at 12:54 AM, Kurt Lidl <lidl@pix.net> wrote:
>
> > On Mon, Jul 09, 2012 at 04:00:19PM +0200, Marius Strobl wrote:
> > > On Sat, Jul 07, 2012 at 10:54:35PM -0400, Kurt Lidl wrote:
> > > > I built a full 9.0-stable distribution on Friday night, and got to play
> > > > with installing it on a spare Netra T1-105 today. Mostly I was
> > > > interested in testing out the integrated ZFS boot support that
> > > > was commited recently.
> > > >
> > > > First of all -- it works! Thanks very much to all who made it
> > possible!
> > > >
> > > > After working through a couple of nits in my script that installs it
> > all,
> > > > I've got a fully functioning, ZFS-only sparc64 machine. Nice.
> > > >
> > > > The zfsboot bootblock's warning about not being able to open
> > non-existant
> > > > devices are pretty extranous, but other than that, it seems to
> > function OK.
> > >
> > > That's more or less a cosmetic problem for now; there's no standard
> > > Open Firmware method allowing to test whether the device corresponding
> > > to a (automatically) created device alias actually exists short of
> > > trying to open it, with OFW causing at least the "Drive not ready"
> > > part on its own. There are some Sun specific extensions to the
> > > default methods whose names sound like they could be of some help
> > > here. I haven't gotten around to actually test whether this is the
> > > case or whether they actually exist in all OFW implementations of
> > > all sun4u models.
> > > If the aliases were artificially created via the `nvalias` command
> > > ("disk9" sounds a bit unusual for the automatically created ones)
> > > you can get rid of the none existing ones via `nvunalias` (needs
> > > a `reset-all` or power-cycle to take effect).
> >
> > All the disks that were probed were part of the normally
> > defined devices on the machine. I only have two devices defined
> > in my nvramrc:
> >
> > ok nvramrc type
> > devalias rootdisk /pci@1f,0/pci@1,1/scsi@2/disk@0,0
> > devalias rootmirror /pci@1f,0/pci@1,1/scsi@2/disk@1,0
> >
> > And I have the system configured to boot from "rootdisk rootmirror".
> >
> > Here's the full output of a 'devalias' from the prom on the machine:
> >
> > ok devalias
> > cdrom1 /pci@1f,0/pci@1,1/scsi@2/disk@6,0:f
> > cdrom /pci@1f,0/pci@1/pci@1/ide@e/cdrom@2:f
> > ide-disk /pci@1f,0/pci@1/pci@1/ide@e/disk@0:f
> > ide-cdrom /pci@1f,0/pci@1/pci@1/ide@e/cdrom@2:f
> > ide /pci@1f,0/pci@1/pci@1/ide@e
> > rootmirror /pci@1f,0/pci@1,1/scsi@2/disk@1,0
> > rootdisk /pci@1f,0/pci@1,1/scsi@2/disk@0,0
> > userprom2 /pci@1f,0/pci@1,1/ebus@1/flashprom@10,800000
> > userprom1 /pci@1f,0/pci@1,1/ebus@1/flashprom@10,400000
> > i2c-cs2 /pci@1f,0/pci@1,1/ebus@1/i2c@14,100000
> > i2c /pci@1f,0/pci@1,1/ebus@1/i2c@14,600000
> > systemprom /pci@1f,0/pci@1,1/ebus@1/flashprom@10,0
> > pcic /pci@1f,0/pci@1/pci@1
> > pcib /pci@1f,0/pci@1,1
> > pcia /pci@1f,0/pci@1
> > ebus /pci@1f,0/pci@1,1/ebus@1
> > net2 /pci@1f,0/pci@1,1/network@3,1
> > net /pci@1f,0/pci@1,1/network@1,1
> > floppy /pci@1f,0/pci@1,1/ebus@1/fdthree
> > disk /pci@1f,0/pci@1,1/scsi@2/disk@0,0
> > cdrom /pci@1f,0/pci@1,1/scsi@2/disk@6,0:f
> > tape /pci@1f,0/pci@1,1/scsi@2/tape@4,0
> > tape1 /pci@1f,0/pci@1,1/scsi@2/tape@5,0
> > tape0 /pci@1f,0/pci@1,1/scsi@2/tape@4,0
> > diskf /pci@1f,0/pci@1,1/scsi@2/disk@f,0
> > diske /pci@1f,0/pci@1,1/scsi@2/disk@e,0
> > diskd /pci@1f,0/pci@1,1/scsi@2/disk@d,0
> > diskc /pci@1f,0/pci@1,1/scsi@2/disk@c,0
> > diskb /pci@1f,0/pci@1,1/scsi@2/disk@b,0
> > diska /pci@1f,0/pci@1,1/scsi@2/disk@a,0
> > disk9 /pci@1f,0/pci@1,1/scsi@2/disk@9,0
> > disk8 /pci@1f,0/pci@1,1/scsi@2/disk@8,0
> > disk7 /pci@1f,0/pci@1,1/scsi@2/disk@7,0
> > disk6 /pci@1f,0/pci@1,1/scsi@2/disk@6,0
> > disk5 /pci@1f,0/pci@1,1/scsi@2/disk@5,0
> > disk4 /pci@1f,0/pci@1,1/scsi@2/disk@4,0
> > disk3 /pci@1f,0/pci@1,1/scsi@2/disk@3,0
> > disk2 /pci@1f,0/pci@1,1/scsi@2/disk@2,0
> > disk1 /pci@1f,0/pci@1,1/scsi@2/disk@1,0
> > disk0 /pci@1f,0/pci@1,1/scsi@2/disk@0,0
> > scsi /pci@1f,0/pci@1,1/scsi@2
> > ttyb /pci@1f,0/pci@1,1/ebus@1/su@14,3602f8
> > ttya /pci@1f,0/pci@1,1/ebus@1/su@14,3803f8
> > ttyd /pci@1f,0/pci@1,1/ebus@1/se@14,400000:b
> > ttyc /pci@1f,0/pci@1,1/ebus@1/se@14,400000:a
> >
> > As you can see, the devices disk0..diskf exist, but something in the
> > boot code "only" probes the first 10 devices. It's certainly not
> > attempting to opening *all* the disk devices listed by 'devalias'.
> >
> > It looks like from the code in .../sys/boot/sparc64/loader/main.c
> > that the first MAXDEV (==31) disk devices are probed (well, whatever
> > disk%d is an alias to, I suppose) and the vtoc's
> > loaded and examined for zfs partitions.
> >
> > oops, I think I assumed that the disk name should be disk9, disk10,
> disk11, instead of disk9, diska, diskb...
> Is there any standards to name those disks?
I do not really know. The above 'devalias' output is the same on
the two netra-T1 105s that I tested. I looked on my SunFire V240,
and it has many fewer entries:
{1} ok devalias
usb /pci@1e,600000/ide@d/disk
xnet2 /pci@1d,700000/pci@1/SUNW,hme@0,1:dhcp,
xnet1 /pci@1e,600000/pci@3/SUNW,hme@0,1:dhcp,
xnet /pci@1e,600000/pci@2/SUNW,hme@0,1:dhcp,
net3 /pci@1d,700000/network@2,1
net2 /pci@1d,700000/network@2
net1 /pci@1f,700000/network@2,1
net /pci@1f,700000/network@2
cdrom /pci@1e,600000/ide@d/cdrom@0,0:f
ide /pci@1e,600000/ide@d
disk3 /pci@1c,600000/scsi@2/disk@3,0
disk2 /pci@1c,600000/scsi@2/disk@2,0
disk1 /pci@1c,600000/scsi@2/disk@1,0
disk0 /pci@1c,600000/scsi@2/disk@0,0
disk /pci@1c,600000/scsi@2/disk@0,0
scsi /pci@1c,600000/scsi@2
sc-control /pci@1e,600000/isa@7/rmc-comm@0,3e8
ttyb /pci@1e,600000/isa@7/serial@0,2e8
ttya /pci@1e,600000/isa@7/serial@0,3f8
name aliases
I would argue that what the loader ought to be looking at the
devices/devalias entries values for the "boot-device" property.
That way, if I wanted to boot from something like a zmirror of
disk2 and disk3 on my sunfire, I would just set the
"boot-device" to be "disk2 disk3", and the zfs boot code would
just try to interate through those devices, rather than going
from 0..31 and trying disk%d...
If I had valid boot-code on disk0 and disk2, and I set the
"boot-device" to "disk2 disk3", I think current code will do
this:
- prom load "zfsboot" block off disk2
- zfsboot block loads in the zfsloader binary from current disk (disk2)
- which then probes disk0, disk1 .... and finally boots
the kernel from the first freebsd-zfs partition that it finds
on any of those disks.
I think this is wrong, as there could be some data-only zfs
partition on disk0, which doesn't have a kernel to boot from...
Also, one other thing to keep in mind that the boot-device propery
can be a devalias entry or just a straight-up device specifier,
like this:
/pci@1c,600000/scsi@2/disk@0,0:a
(That's what I have on my SunFire, for various arcane reasons...)
I guess we also have to worry when someone breaks into the prom
and says "boot disk4", and that user input should override the
"boot-device" settings in the prom.
-Kurt
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