[NTLUG:Discuss] SCSI drives

Thu Dec 5 11:55:25 CST 2002

I love scsi's for one big reason:  heat tolerance.
I have two servers with scsi's, one being a dual CPU.
I have two servers with ide's--one if those is an old
233Mhz and the other is a 750Mhz.  I have one 'machine'
with win98 installed (my kid's machine, so I'm stuck with it).
I do not have air conditioning (nor will I *ever*--I'm far too cheap).

Over the course of 8 years, I've had one scsi drive fail, that on 
my Sol x86 which is my mailserver/nameserver and has *lots* of read/writes;
over the course of 2 years, I have had no failures on my Linux server
with the two scsi drives and dual CPU's.  Over the course of one year, my
750Mhz ide machine has had one drive failure.  I will say that
my little 233Mhz machine with the ide keeps on ticking, but he does
does very little so has no significant disk activity to stress him.
The win98 machine with the ide doesn't count because it's down 
about as much as it's up.

In any case, I'll always go with scsi's, even if they cost more--in the 
long run, they've proven themselves to be more cost efficient, their
other virtues, aside.

Annette

PS--I do have these machines well equipped with drive bay fans--even
scsi's aren't totally magic when it comes to heat.

> From sjbaker1 at airmail.net Thu Dec  5 11:30:22 2002
> From: Steve Baker <sjbaker1 at airmail.net>
> User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.8) Gecko/20020204
> X-Accept-Language: en-us
> MIME-Version: 1.0
> To: discuss at ntlug.org
> Subject: Re: [NTLUG:Discuss] SCSI drives
> Content-Transfer-Encoding: 7bit
> X-BeenThere: discuss at ntlug.org
> X-Mailman-Version: 2.0.13
> List-Help: <mailto:discuss-request at ntlug.org?subject=help>
> List-Post: <mailto:discuss at ntlug.org>
> List-Subscribe: <https://ntlug.org/mailman/listinfo/discuss>,
> 	<mailto:discuss-request at ntlug.org?subject=subscribe>
> List-Id: NTLUG Discussion List <discuss.ntlug.org>
> List-Unsubscribe: <https://ntlug.org/mailman/listinfo/discuss>,
> 	<mailto:discuss-request at ntlug.org?subject=unsubscribe>
> List-Archive: <https://ntlug.org/pipermail/discuss/>
> Date: Thu, 05 Dec 2002 11:21:47 -0600
> 
> 
> 
> Vaidya, Harshal (Cognizant) wrote:
> 
> >   Can anybody explain me what is the difference between a normal Hard Drive
> > and SCSI drive.
> 
> 
> SHORT ANSWER: They use a different bus connection.  You can't just plug a
>                SCSI drive into your motherboard.
> 
> LONG ANSWER:
> 
> 'Normal' hard drives connect via the IDE interface which only allows (I think)
> two drives per interface.  Most PC's have two interfaces - limiting you to four
> drives total.
> 
> SCSI drives use the SCSI (Small Computer System Interconnect) interface which
> allows a wide variety of devices to be connected to the bus (not just disk
> drives) and can have up to (IIRC) sixteen peripherals connected to it.  The
> SCSI standard is rather overkill for disk drives because it allows for all
> sorts of sophisticated behaviors that disk drives don't need.  My scanner
> is interfaced via SCSI for example.
> 
> Historically, SCSI drives have been more expensive and faster than IDE drives.
> 
> However, with the more recent varients of IDE and SCSI, I've rather lost track
> of which is better these days.
> 
> Additionally, most motherboards lack a SCSI bus connection - so you'll probably
> have to go and buy a SCSI adaptor.
> 
> SCSI is also better suited to external drives than IDE because it's electrical
> specification allows for much longer cables than IDE - and there is a standard
> connector that's better suited to external ports than the flimsy IDE connector.
> External SCSI devices are 'daisy-chained' - so each device has an input and an
> output connector - the last one in the chain has to have a 'terminator' plugged
> into it's output port.
> 
> Some software (eg CD-burners) *REQUIRE* a SCSI interface - Linux has a SCSI
> emulator that can make IDE devices appear to be SCSI devices even though
> they are not connected that way.
> 
> CONCLUSIONS:
> 
> * For most uses, get an IDE drive and just plug it in and go.
> 
> * If you need more than 4 drives in your PC (bearing in mind that
>    your DVD and CD-ROM drives are probably on the IDE bus) - get SCSI.
> 
> * If you really, deeply care about disk performance then you'll
>    want to do a TON more research - and you may well find that
>    SCSI is still the better interface.
> 
> * Don't buy a SCSI drive without bearing in mind the need for s
>    SCSI adaptor card in your PC.
> 
> ---------------------------- Steve Baker -------------------------
> HomeEmail: <sjbaker1 at airmail.net>    WorkEmail: <sjbaker at link.com>
> HomePage : http://web2.airmail.net/sjbaker1
> Projects : http://plib.sf.net    http://tuxaqfh.sf.net
>             http://tuxkart.sf.net http://prettypoly.sf.net
> 
> 
> _______________________________________________
> https://ntlug.org/mailman/listinfo/discuss
> 