Active slice, only for a next boot

[Julian Elischer]

On 5/28/11 6:06 AM, rank1seeker at gmail.com wrote:
> And how about this:
>
> # boot0cfg -o noupdate -s 1
> Now when you choose to hit slice 2, it is only for a this one boot.
> Next and each boot, defaults to slice 1
>
> Problem is, that you must see, early bootstrap, to manually choose, so this won't work on a remote server.
> This requires:
> a) physicall access
>     or
> b) ssh access to the remote box, which is conected via serial cable, to your server.
>
> Anyone has any idea, for a case of a remote server, which is accessible over ssh, only when it is "up"?

pull the old bootblocks from about 2000 and use them.
and nextboot as well
they do exactly what you want.

OR

ask Doug Ambrisko (cc'd) for a copy of them that he still uses at work.
He may have updates to make them work with modern systems that would 
save you time.

the old nextboot(8) stored instructions as to what to do on block 1 of 
the drive
  (you can make it a small 1 block partition if you want). Actually it 
stored a series of them, NULL separated.
On each boot the boot 0 bloter would read the first (after skipping 
any nulls) and then write Nulls over
what it just read and write it back to block 1.
so it would progress gradualy boot by boot over the sequence written 
by nextboot.

it would pass on the stack, what it had read to boot1.


the format was "hd(1,a)/boot/loader"    (for example)
personally I would like to hav ethis capabiltiy back because it's 
stupid  rely on a
possibly dead filesystem to get around booting from the possibly dead 
filesystem.

by default we used to have a /etc/rc entry that would rewrite the 
'current' setup several times on successful boot,
followed by a couple of alternate boot targets.
If boot failed a coupke of times it would automatically boot from the 
second drive or from another partition,
..




>
> Domagoj Smolčić
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