Justin sez:
# >*smeksmeksmek* Hey!  WAKE UP!
# >
# >	--> mirroring != striping <--
# 
# It amazes me how rude people are during technical discussions.
# First I have to read things like "Hint: <blah>", now this.  
# It doesn't make it any less rude if the comments are technically
# incorrect.  Lets keep the discussion on a technical basis, please.

<non-technical-diatribe>

Two words, Justin:  lighten up.  I was not trying to be rude, I was
trying to interject some humour into an obviously missed point.
I was saying something different than you were reading, and I wanted
to make sure you got it.

I should probably have interjected a smiley.  Even so, this is no
reason to get nasty about it.

Would you have preferred I said something like, "What are you,
an idiot?  I said nothing about mirroring, I said *striping*.
There _is_ a difference."????  I didn't think so, that would have
been both generally REALLY rude, and completely uncharacteristic
of my contributions to this forum.  Please, by the way, don't
consider that I would have even *thought* of saying that, because
I wasn't even thinking anything along those lines at the time.

I don't claim to know everything, and I never will.  I _do_ believe
myself to have a fairly good grasp of the concepts, however ill my
ability to actually code such concepts.

</non-technical-diatribe>

# 
# Of course mirroring != striping.  From the point of design, it
# doesn't matter that that they are.  The point is that you should
# be able to apply VM management to *any* partition even if some
# of the formating choices are restricted by the way a particular 
# machine boots.

That gets really ugly, though, and it adds quite a bit of bloat to
an otherwise performance-wise streamlined design.  I don't think
the tradeoff is worth it.  At the very least, you'd need a three-
stage booter to accomplish the task, as opposed to the two-stage
model we have now.  I'll illustrate that if you wish, but I think
it would be redundant to do so since you are endowed with sufficient
logistical skills to arrive at the conclusion on your own.

# 
# >I think _mirroring_ the root drive is a good idea.
# >
# >I think _striping_ the root drive is suicidal.
# 
# RAID 5 is a form of striping and wouldn't necessarily be overkill
# especially if you consider that what I really want to do with my
# 5 identical disks is to stripe *all* of their space regardless of
# the fact that a small part of the total space is / and /usr.

RAID 5, again, is a time/reliability trade.  If you need that level
of reliability, okay, that's an all right thing, but RAID 5 is slow
in hardware and slower in software.  And, of course, I don't need it
as much as others do.  If it's something you wish to implement, I _do_
support your (and others) effort.  But I object if the implementation
is going to add another layer to the already laden filesystem interface.
If it's going to slow me down, I don't want it on my system, not
even in the form of hooks, because that means I'm still going to end
up going through another layer, be it null or not.  A null layer is
still an extra layer, and func(){} still takes time to execute.
But I'm rambling, as I'm sure you'll be happy to point out.

First there was the inode-layered filesystem.  Then we got vnodes due
to NFS.  Then they implemented the fsswitch on top of that or in
between the first two.  That's three layers already.  I'd rather
the fourth was an option.

# My
# other choice is to either lose part of all 5 disks from my stripe
# set, or buy two additional disks so that I can mirror just / and /usr.
# The fact that some machines prevent you from booting to a striped
# volume sucks, but that doesn't mean that your design shouldn't
# allow it for those that can.

You have a third choice:  Stripe 4 out of 5, and put /usr on a
different spindle from /.

Fourth:  have an /altroot hanging around (or a mirrored root), and
on the other three drives, use that space as swap space.  Give you
one hell of a /tmp partition! :-)

<personal>
Finally, I want you to realise that I am not intentionally being
callous, nor are my remarks intended to be rude.  If I come across
that way, I do apologise.
</personal>

# 
# >				--*greywolf;
# 
# --
# Justin T. Gibbs
# ===========================================
#   FreeBSD: Turning PCs into workstations
# ===========================================