SUMMARY: alt boot disk in ext SSA100 fails to boot - wrong devalias or not bootable?

From: Adam Singer (
Date: Mon Apr 12 1999 - 00:15:09 CDT

Dear Sun Managers,

I am following up my own email request with the solution (original
post is at the end). While no one here or in the newsgroups sent me
anything, I was able to get my answer from an internal Sun Infodoc
that the support guy kindly sent to me. It is in fact possible to
boot from an SSA but one of the internal docs does not recommend this
while the one with the solution below had no such admonition. The key
was that the full boot path does not follow exactly the boot path
"style" of the internal or other scsi disks - instead an extra "SUNW,"
is added. Here is the mini-howto I wrote up for myself. I hope it
helps someone out.

If you want to see how disk and ssaboot are defined, type
     ok> devalias
Once you have selected a disk to use as the 2nd boot disk, type
     ls -l /dev/dsk/c3t0d0s0
The path it gives you will be the path you put in the devalias command
at the boot prompt except you will not use the ../../devices part and
at the end you will cut off the :a part and insert SUNW in front of
the ssd@ stuff.
So ../../devices/io-unit@f,e1200000/sbi@0,0/SUNW,soc@3,0/SUNW,pln@
So once you have this info, bring the system down to the OK prompt:
     ok setenv auto-boot? false
     ok devalias (just to see what is there)
     ok nvalias ssaboot
         (note the ssaboot is an arbitrary name, can be anything and
everything is on one line but wraps due to its length).
     ok nvstore (to save it)
     ok reset (with auto-boot? false)
     ok devalias (make sure the name stuck)
     ok boot ssaboot - should boot off the new disk


>Dear Sun Managers
>I am trying to create a 2nd boot disk for our Sparc 1000 (not a 1000E)
>running 2.6 on the boot disk. The 1000 has 4 500mb internal drives
>and we can't use any of them so I had wanted to create an external
>boot disk on one of our external SSA's because the developers need to
>try some stuff under 2.5.1.
>Questions I have about the feasability of this are:
>1. is it possible to boot off an external disk that is in an SSA100
>(not 112)? I worry no because maybe the fiber-optic/soc stuff needs
>to first be loaded in kernel before the system can even see the disks.
>2. if it is not possible, can I take one of the 2.1GB drives and put
>it inside the unit, replacing one of the 500mb disks or replacing two
>500mb disks with 2.1GB or is the 1000's heat and power only rated for
>the smaller disks? Where could I get this information, I couldn't
>seem to find it while searching on Sun's site or the mailing list
>On the hope that it would be possible to get this working, I
>successfully installed 2.5.1 on the disk I chose (c3t0d1). However,
>for every permutation of the device path (see below) I tried, the
>system said "cannot find boot device." All the examples (from usenet
>and mailing list) were for other architectures, but by doing a
>devalias and looking at how disk, disk1, etc. were structured and by
>taking the ls -al output of /dev/dsk/c0t0d0s0 and c3t0d1s0 I thought I
>could stitch the path together.
>Here is the ls of /dev/dsk:
>The PROM's identification of the boot disk is almost identical to the
>line above for c0t0d0s0 but "disk" has /sbi/ instead of /sbi@0,0/.
>Also the definition for "disk" did not have the actual slice (:a) on
>the end. Well I tried w/ & w/out both and each 0,0 and the :a.
>Naturally my line was slightly different given the hardware path, but
>they went mostly like this:
>nvalias disk251 /io-unit@f,e1200000/sbi/SUNW,soc@3,0/
>(also tried w/ :a and w/ 0,0 and with both together).
>Since none of the above worked I am wondering if it is even possible,
>if it is I would be greatful for the magic combo and maybe even
>references to where I too could get this info in its original form.
>Tips on whether I can put 2.1GB drives in the 1000 are also
>appreciated as well as where I too could have gotten that info.
>thanks in advance,


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