Boot from Raid

[leavitt@webcom.com]

> 
> We have an 18 disk SSA110 Sun Array connected to a 4000 running Solaris =
> 2.51. We would like to boot the 4000 from the raid and mirror the root =
> volume. Is there any danger to booting booting from the array? Is there =
> any documentation that can help expedite the process?  Thanks
> 

This is supported, but generally not recommended (informally), according
to nearly ever Sun engineer I've spoken to (the people who get to fix
things when they break). Basically, it adds a very significant layer
of complexity to the booting process, relatively little protection,
and vastly increases the complexity of upgrades of both the volume
manager and the OS, as well as decreasing the "portability" of the
data on the storage array.

The recommended method of disaster recovered is "high-availability"...
dd your root disk to an equivalent internal disk on a nightly basis.

When your primary disk dies, or someone pulls a bonehead manuever
like rm -r /bin, or a patch upgrade or backout goes bad, instead of
having to recover from tape, or reconstruct everything, you do
a "break", go down to the "ok" prompt, and type "boot disk1" 
(or equivalent), and you're back up. Further, apparently, if your
primary disk goes bad, and your system crashes, it will try and
boot off the bad disk, and failing that, fall back to the secondary
disk ("disk1"). Not sure how to set this up, or whether it is
automatic.

Regards,
Thomas Leavitt


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