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Date:      Sun, 3 Sep 2000 01:48:57 -0400 (EDT)
From:      Adam <bsdx@looksharp.net>
To:        freebsd-hackers@FreeBSD.ORG
Subject:   Re: Cheap 1000Gbyte machine
Message-ID:  <Pine.BSF.4.21.0009030148070.11096-100000@turtle.looksharp.net>

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Passing this on... :)

---------- Forwarded message ----------
Date: Tue, 22 Aug 2000 20:31:00 -0400 (EDT)
From: General Lee D Mented <gldm@mail.com>
To: bsdx@looksharp.net
Subject: FWD: Re: Cheap 1000Gbyte machine (fwd)

>On Fri, 18 Aug 2000, Jonathan Laventhol wrote:
>
>> Hello Folks --
>>
>> Anybody built a file server with approx 1000 Gbyte or more?
>> Or even 200 Gbyte?
>>
>> I'm looking for a cheap simple way of doing this.  Lots of
>> IDE drives?  (How many can you have?)  Or SCSI?  (Again,
>> how many can you have?).
>>
>> It's for lots of 1 Mbyte files: no huge files.
>>
>> Thanks for any tips.
>
>You might want to check out the Arena Industrial II Rackmount RAID system
>from "www.raidweb.com".  It has 8 x UDMA controllers that connect to the
>host via Ultra2 SCSI (platform independant).  Buy two (or more) of those
>and 16 x (60/80 gb Maxtor UMDA Drives or 75 gb IBM UMDA Drives).
>
>2  x Arena Industrial II Rackmount RAID  $3,975
>16 x Maxtor UDMA 60 gb Hard Drives       $3,680
>
>Total Cost                               $7,655
>
>That comes out to about $7.98 / gb...
>
>---
>Mike Wade (mwade@cdc.net)


There's several ways to go about this, the stupid way, the cheap way, the
efficient way, and the expensive way.

The stupid way is to throw 4 or more Fastrak controllers into a motherboard
and hope it works. Yes, I know, 4 drives per controller, some controllers
have RAID. Well the RAID is really 99.9% software anyway, (otherwise why
would it be so easy to modify the non-RAID controller into one?) and because
of master/slave you can't access all the drives at once, and there's no
write cache, command queue, or sorting, so your write performance will suck
balls. You really want high rpm drives for this because drive latency is
severely going to cripple you and be the limiting factor.

Cost: $20 per controller x 4 = 80 controller cost
$420 per HD (IBM 75GXP 60GB) = 6720 drive cost

cost per TB = $7083

The cheap way is to get 2x 3ware Escalade 6800s and start loading large IDE
drives, like 60 or 75GB IBM 75GXP, or 61.4GB Maxtor 96147U8. This will cut
your cpu load way down, save slots, and still be relatively cheap. 7200 vs
5400rpm is fairly moot as 16 drives in parallel need to only sustain
8.25MB/sec each to saturate PCI's theoretical limits. The latency due to
lower spindle speed isn't as great an issue because of 3ware's command queue
and sort (normally a scsi-only feature).

Cost: $279 per controller x2 = $558
$225 per HD (Maxtor 61.4GB) x16 = $3600

cost per TB = $4232

The efficient way is to optimize the system for sustainable bandwidth. Most
servers aren't too CPU intensive, rather more memory or disk intensive. Thus
you can go with slightly older highend hardware but get better results than
current mainstream hardware. For example, a SuperMicro P6DLH, and some AMI
MegaRAID 466s. The P6DLH is an LX based motherboard with 9PCI and an I2O
compliant i960 coprocessor onboard. The concept is that I2O compliant
devices (like the MegaRAID and some network cards) can send and recieve data
to and from each other and system ram via the i960, without bothering the
host CPU. This usually results in much less overhead per memory transfer.
These controllers also support large onboard caches (16MB stock, up to 128MB
FPM Parity SIMMs) to greatly improve write performance. The downside is of
course, the cost involved. For hard drives, the best pricepoint is currently
the Quantum Atlas V 36.7GB. (Yes even better than the 47GB Elite when I
checked.)

Cost: $199 for the motherboard = $199
$149 x2 for controller = $149
$475 x27 for drives = $12825

cost per TB = $13294


The expensive way is to just go flat out for the highest performing
hardware, which is a mistake because even our cheap solution was already
saturating the PCI bus, and even if we double that performance we could
build several cheap solutions for less than one expensive one. This route
would be the SuperMicro S2QR6, which is a Quad Xeon Serverworks board
featuring 64bit PCI, a DPT PM3755F-2F 64bit PCI controller with dual
fiberchannel loops and 256MB cache onboard, and a LARGE number of
fiberchannel cheetah x15s. This is far beyond overkill given how badly even
64bit PCI will cripple the system.

Cost: $2555 for the motherboard = $2555
$1532 for the base DPT = $1532
$282 x 4 for 64MB cache modules = $1128
$480 x 54 for cheetah x15s = $25920

cost per TB = $31336


All this still neglects the cost of case, powersupply, cpu, etc. As we can
see, 3ware is by far the cheapest. "But what about the promise with the
cheap HDs?", you ask. Even with 7200rpm drives the conflicts are going to
kill its performance with only a few users. I don't even want to consider it
on 5400rpm drives, as it probably would spend so much time waiting for seeks
and changing master/slave and syncing spindles to complete RAID stripes that
it wouldn't be very useful.


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