SUMMARY: E10000 boot disk booting on a E420 - long & interesting

Hi Forumers,

This will be an incomplete summary since we have not tried anything in
practice yet, but the steps are pretty outlined.

Thanks a bunch for the quick and useful replies from

Derek Olsen
Matt Ungaro
Buddy Lumpkin
Steve Camp
Anand Chouthai

as well as the fellas who remembered us that someone is having fun in other
places than datacerters.

Original post:

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Hi fellow managers,

Does anyone tried to make Solaris 8 boot disk installed on an E1000 bootable
in other platform sun4u (E6500 in this case) ? Is that possible?

What we are planning to achieve that:

- Make a third mirror of an E10000 boot disk (via SDS).
- Make this disk bootable
- Deattach the disk. Remove this disk..
- In a running E420 with a slot free, insert this disk.
- Mount the root partitions. Remove all the contents of the /devices
- Remove path_to_ inst
- Configure sd.conf properly.
- Boot this disk, forcing reconfiguration.
- Voila?

Will it work? Any missing steps?

Any help is greatly appreciated.

Filipe.
_______________________________________________


Matt Replied:

"You could cut some of those steps, place the boot disk in, and on first boot
do a boot -ar. This will reconstruct the path_to_inst and recreate /dev
entries. In theory, this should work. But theory and reality aren't always
one in the same.

Matt"

That may work with all regular systems, but the problem is that when a system
installed in a E10k domain boots, it looks for the control board, starts
daemons like cvcd and other platform related processes.

Ryan told us a desencouraging story:

Just an FYI.  We tried doing this for Disaster Recovery purposes.  Sun
does not support this method at all.  Yes, "technically" it should work.
You will also need to regenerate your path_to_inst.  Make sure you boot
the system with boot -ar (this should regenerate path_to_inst).

We tried doing this but were only able to get the system and running in
single user mode. (SBUS to SBUS arch. or PCI to PCI arch.)

Oh, you know what...E420...no go.  Two different architechtures.  E420 is
PCI and E10K is SBUS.  This will most definetly will not work at all.

It is certainly not hard to figure out that Sun would not bet on it. But an
E10k can work with both PCI or SBUS, depending on how you configured your
system boards. And both are "sun4u".

Derek sent us a useful receipe for making "transplated" boot disk works.

# Need to get rid of device trees since the will not work from one box
# to the next.  Also need to nuke the path_to_inst file.
rm -rf /a/dev /a/devices
rm /a/etc/path_to_inst

# Need to restore the device tree from what is actually created during
# the net boot process.
cd /
find devices dev -depth -print | cpio -pdm /a

# Now we need to create a new path_to_inst
devfsadm -r /a -p /a/etc/path_to_inst

# Need to recreate dev entries that got blown away
devfsadm -i random -i ipf -i md -r /a -p /a/etc/path_to_inst


That would be great, but when dealing with an E10k domain, things get a bit
complicated...

Matt Ungaro basically agreed to Derek.

Buddy sent us his detailed receipt.


detach the submirror for this disk (third mirror as you describe below)
mount the underlying disk slice of that disk to /mnt
edit /mnt/etc/system and uncomment line that sets rootdev
edit /mnt/etc/vfstab and change lines from metavolumes to /dev/dsk/cxtxdxsx
run the following commands:

rm -r /mnt/devices
rm -r /mnt/dev

Pre-Solaris 8:

rm /mnt/etc/path_to_inst

drvconfig -R /mnt
devlinks -R /mnt
disks -R /mnt
ports -R /mnt

Solaris 8 or newer:

devfsadm -p /mnt/etc/path_to_inst -r /mnt

Now on Solaris 2.6, boot from new disk with -a option and when prompted,
re-create path_to_inst. Although it is undocumented, -p option to devfsadm
does this automatically (truss it and you will see). It doesn't work with
drvconfig though.

For Solaris 8 or newer, your done. Boot from the new disk.

Steve gave us his outlook:

(...)
I think you may have to install a new bootblock on the "transplanted" disk.
I am concerned that the kernel ( /kernel/genunix ) is for a Sun4U-1
architecture
(E10K), but you are doing to attempt to run it on a Sun4U architecture (E420
aka
Ultra80)... and I fear the consequences.  Also, anything on that transplanted
disk that references /platform/<architecture> or /usr/platform/<architecture>
will be potential problems.

I am fairly certain that what you propose is "unsupported" by Sun and is the
kind of thing that would cause me and my fellow call center E10K support
engineers to shake our head in wonder at the stupidity of our customer(s)
and wonder just what the hell they were thinking.

(...)

Oh, don't forget to disable all /etc/init.d/ startup scripts that attempt
to start all sorts of E10K-specific daemons etc.

Great feedback of an evidently experienced professional. Other reply from him
(about booting only to a single-user mode)

(...)
My guess:  some E10K specific scripts and/or daemons are stopping the boot
           process;  they may be logging errors, or they may be waiting to
	   speak to a non-existent control board or SSP.  Without
	   /var/adm/messages and/or `dmesg' output and/or /var/log/syslog
	   log files (among possibly other files)... I can only speculate
	   at this point.
(...)

An then, Anand Chouthai came along. He told he works with such scenarios for
living.

Yes , it will work, One of the steps I see missing is to take out any
references to ssp. Also it will work 99% times if the original E10 install
is done Entire distribution with OEM support.

(...)

And at last what seems to be the "voila"


Take the disk which has the E10K image and put it on E420R:
   Boot from cdrom in single user mode ( same OS on the E10K image) or boot
   from jumpstart in single user mode
   mount the disk with the E10000 image on /a
   cd /a
   mv dev dev.dr
   mv devices devices.dr
   mkdir dev devices
   cd /dev
   find . -depth -print | cpio -pdm /a/dev
   cd /devices
   find . -depth -print | cpio -pdm /a/devices
   cd /a/etc
   mv path_to_inst path_to_inst.dr
   cp /tmp/root/etc/path_to_inst .
   change the vfstab to appropriate disk config
   If the E10000 disk was encapsulated then take the rootdev entries out
   from system file
   install bootblk on the disk
   cd /a/etc
   mv ssphostname ssphostname.dr
   init 0
   ok> boot  -rasvw
   when it comes to single user mode <ctrl D> to go to multi user mode.

Hope it works. Good luck.

Well, thats all. As I mentioned, we didn4t try it yet, but it seems to be the
way to get the work done. Anyway I will let the list know how it worked.

Regards,

Filipe Barbosa Litaiff
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