Newsgroups: bit.listserv.novell
Date:         Wed, 6 Jan 1993 20:36:00 CST
Reply-To:     Novell LAN Interest Group <NOVELL@SUVM.BITNET>
From:         Netman@PHYSLOG-PO.PHYSLOG.UIOWA.EDU
Subject: Re: Server Fault Tolerant H/W Sources Sought

>In response to my query for sources for fault tolerant hardware for our
>NetWare file server.....

>Yes, Del, I -really- need at least -some- form of more-or-less
>automatic-failover
>fault tolerance, though you are right that RAID seems like "swatting flies."
>RAID is only one of the options I am looking at; what I am trying to do is to
>perform a costs-benefits analysis vis a vis different levels of fault
>tolerance in hardware and software.

Yo Tom!

I hear you.  While I don't expect to have quite the number of
users hanging off my server as you, what my users lack in
quantity they make up for in impertinence.

I am looking at RAID as well as SFT III.  But the RAID solutions
I've seen so far are pricey and they only address the storage
component of the server.  If the power supply, the controller, or
the motherboard fail, we're in the same stew. (Or worse yet the
keyboard starts sending wierd codes to the console which makes it
seem that the video board is bad although things get a little bit
better when you replace the hard disk controller and then the
network card starts acting flakey and only improves when the CMOS
battery is replaced and the EISA configuration routine is run a
half dozen times, but only from the floppy drive...)

When my Model 80 motherboard went "fiszt" a couple years ago
(while our university's "spare" server was in use elsewhere) I
spent almost two weeks waiting for a replacement board that
actually worked and discovered what real misery is.

What I chose to do last spring was to buy two server capable
machines.  I chose Gateway 2000 because I am confident of their
popular name brand components and I could buy two identical 486
33MHz machines for the cost of a more upscale machine.  (Nothing
propiatary here, if Gateway went under tomorrow, I'd be able to
find a dozen vendors selling the same components at competitive
prices.)  I did buy the 1GB SCSI hard drives elsewhere, though.
(Micropolis, relatively fast, relatively cheap, 5 year warranty.)

So one machine hums away as a very impressive server and the
other sits alongside my desk and makes my programming tasks a
little more pleasant.

In the event of disaster, I have a full complement of spare
parts.  If the culprit is obvious, I can swap a part from my
spare and borrow the work study student's Model 50Z while I await
a replacement.  If the cause is one of those infamous murky
nasties, I can move the server's hard disk to my spare machine
and fire it up within minutes.  In the worst possible scenario --
the server's hard disk trashes -- I swap in the spare's (which
has only a 80MB DOS partition and already contains a prepared
Netware partiton with my Cheyenne backup software installed), do
a restore from last night's tape, make formal apologies to the
users and fire up the replacement in two hours time. (I actually
did this and timed it.)

Today I am needing to add more space to the server.  As far as I
can see, I'm still able to purchase another 1GB drive for the
server and rely on a single spare disk.

So what are the tradeoffs?  I can't insure that every last
transaction will be safe.  I stand the chance of seeing a disk
error bring down the network for a few hours.  I could end up
programming on a Model 50Z for a week.  In return, I have a
broader insurance policy that covers the whole server.  I have an
additional productive piece of hardware (if the server never
fails -- knock wood-- I'll still have gotten my mileage out of
the spare.)  And I have saved a mint. (Well, actually the
difference between a $14,000 RAID and a $4,500 spare server.)

Another interesting point for those working in large institutions
which have cumbersome purchasing policies:  I sat down awhile
back with our chief purchasing officer and got him to approve a
list of big ticket critical network components (concentrators,
hard disks, CPUs, etc.) that I could purchase on a moment's
notice if he wasn't available to approve at the critical
juncture.  This, coupled with a short list of vendors who stock
the parts I might need, gives me a slightly more sound night's
sleep. (Well, as good a night as one can expect with a network
and two small children to care for...)

I hope I haven't waxed to lengthy..

Cheers!

-- Cliff

P.S.  Anyone who sees big gaping holes in my strategy is stongly
encouraged to ruin my day. (Better than I should find out in
practice.) Other tips and suggestions would be most welcome.
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU