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Lawrence Stewart | 1 Aug 2010 16:02

Re: Scale modl Cray-1

http://simh.trailing-edge.org or google simh

there are many machines and an active community. the effort is coordinated by Bob Supnik, ex from many
machine projects at Digital. he credits me with the original idea for the project, but that is way too much credit.

simh mostly has minicomputers and older machines. software is available for most of them.

for a while Bob was my boss at SiCortex, and one year at SC we had 12 emulators running simultaneously on one of
the 72 core deskside machines. fun.

-Larry

On Jul 30, 2010, at 11:15 AM, Gus Correa <gus <at> ldeo.columbia.edu> wrote:

> Hearns, John wrote:
>> Enjoy.  http://www.theregister.co.uk/2010/07/29/cray_1_replica/
>> The contents of this email are confidential and for the exclusive use of the intended recipient.  If you
receive this email in error you should not copy it, retransmit it, use it or disclose its contents but
should return it to the sender immediately and delete your copy.
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>> To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
> 
> 
> In this age of virtualization,
> I was wondering if there are simulators in software (say, for Linux)
> of famous old computers: PDP-11, VAX, Cray-1, IBM 1130, IBM/360,
> CDC 6600, even the ENIAC perhaps.
> From instruction set, to OS, to applications.
>
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Gus Correa | 2 Aug 2010 04:02
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Re: Scale modl Cray-1

Thank you all who responded:
Larry Stewart, David Lombard, Franklin Jones,
Douglas Guptill, Thomasz Rolla, Jim Lux.

Glad to see that many of you had not only thought of this,
but actually implemented simulators for many outstanding computers.

I compiled SIMH.

However, I suppose I need to load software to actually simulate
each computer (Assembler? OS? other more specific sw?), correct?

If yes, is this software available, and where?

Any documentation on how to run them?

Many thanks,
Gus Correa

Lawrence Stewart wrote:
> http://simh.trailing-edge.org or google simh
> 
> there are many machines and an active community. the effort is coordinated by Bob Supnik, ex from many
machine projects at Digital. he credits me with the original idea for the project, but that is way too much credit.
> 
> simh mostly has minicomputers and older machines. software is available for most of them.
> 
> for a while Bob was my boss at SiCortex, and one year at SC we had 12 emulators running simultaneously on one
of the 72 core deskside machines. fun.
>
(Continue reading)

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David N. Lombard | 2 Aug 2010 17:15
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Re: Scale modl Cray-1

On Sun, Aug 01, 2010 at 07:02:09PM -0700, Gus Correa wrote:
> Thank you all who responded:
> Larry Stewart, David Lombard, Franklin Jones,
> Douglas Guptill, Thomasz Rolla, Jim Lux.
> 
> Glad to see that many of you had not only thought of this,
> but actually implemented simulators for many outstanding computers.
> 
> I compiled SIMH.
> 
> However, I suppose I need to load software to actually simulate
> each computer (Assembler? OS? other more specific sw?), correct?
> 
> If yes, is this software available, and where?

The 1130 sw is available from ibm1130.org
<http://ibm1130.org/sim/downloads>.

I expect that type of software will usually only be available from
the people and projects that are interested in the simulated system.

> Any documentation on how to run them?

The 1130 sw is sufficiently documented to run it.  I've run it--and
as expected--it *does* run faster than the original hw.

--

-- 
David N. Lombard, Intel, Irvine, CA
I do not speak for Intel Corporation; all comments are strictly my own.
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Rahul Nabar | 5 Aug 2010 23:47
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what defines "enterprise class" hard drives?

I wanted to buy some 1 Terabyte SATA drives for our storage array and
wanted to stay away from the cheap desktop stuff. But each
manufacturer has some "enterprise class drives". But is there
something specific to look for? Most of those seem to have a MTBF of
around 1.2 million hours and a URE of about 1 in 10^15. The S.M.A.R.T.
abilities seem fairly standard.  Is there a list somewhere of well
tested drives? Or any recommendations?

--

-- 
Rahul
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Jon Forrest | 6 Aug 2010 00:33
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Favicon

Re: what defines "enterprise class" hard drives?

On 8/5/2010 2:47 PM, Rahul Nabar wrote:
> I wanted to buy some 1 Terabyte SATA drives for our storage array and
> wanted to stay away from the cheap desktop stuff. But each
> manufacturer has some "enterprise class drives". But is there
> something specific to look for? Most of those seem to have a MTBF of
> around 1.2 million hours and a URE of about 1 in 10^15. The S.M.A.R.T.
> abilities seem fairly standard.  Is there a list somewhere of well
> tested drives? Or any recommendations?

We've talked about this topic on this list
before. There are several schools of thought.
Some people base their opinions on the manufacturer's
claims, and some people base their opinions
on the famous papers from Google and CMU that
came out a couple of years ago that described
how very large numbers of drives really work.

It's an interesting topic, no doubt.

Cordially,

--

-- 
Jon Forrest
Research Computing Support
College of Chemistry
173 Tan Hall
University of California Berkeley
Berkeley, CA
94720-1460
510-643-1032
(Continue reading)

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Rahul Nabar | 6 Aug 2010 00:42
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Re: what defines "enterprise class" hard drives?

On Thu, Aug 5, 2010 at 5:33 PM, Jon Forrest <jlforrest <at> berkeley.edu> wrote:
> We've talked about this topic on this list
> before. There are several schools of thought.
> Some people base their opinions on the manufacturer's
> claims, and some people base their opinions
> on the famous papers from Google and CMU that
> came out a couple of years ago that described
> how very large numbers of drives really work.
>
> It's an interesting topic, no doubt.

Ah! The google hard disk list. Thanks! I totally forgot about that
one. I'll look there.

--

-- 
Rahul
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Rahul Nabar | 6 Aug 2010 00:44
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Re: what defines "enterprise class" hard drives?

On Thu, Aug 5, 2010 at 5:34 PM, Perry E. Metzger <perry <at> piermont.com> wrote:
> On Thu, 5 Aug 2010 16:47:19 -0500 Rahul Nabar <rpnabar <at> gmail.com>
> wrote:
>> I wanted to buy some 1 Terabyte SATA drives for our storage array
>> and wanted to stay away from the cheap desktop stuff. But each
>> manufacturer has some "enterprise class drives". But is there
>> something specific to look for? Most of those seem to have a MTBF of
>> around 1.2 million hours and a URE of about 1 in 10^15. The
>> S.M.A.R.T. abilities seem fairly standard.  Is there a list
>> somewhere of well tested drives? Or any recommendations?
>
> Why do you want to pay more for drives?
>
> If you have hundreds or thousands of machines, you will get failures
> no matter what, so you will need to set up your software to deal with
> failures no matter what. Assuming that a failure doesn't cause you
> much harm, you might as well simply accept a slightly higher failure
> rate in exchange for being able to pay less per node, which lets you
> buy more nodes. You can always keep spares, and indeed, you will have
> to in either case.

Sure, I do have a RAID level on it so a failure per-se isn't disaster.
And I wouldn't pay a $1000 dollar premium for it. But I wouldn't mind
paying $50 more if it translates to less trips to the cluster room and
fewer RAID rebuilds.

That's why I'm trying to buy something better than a cheap run-of-the
mill from newegg.

--

--
(Continue reading)

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Sabuj Pattanayek | 6 Aug 2010 00:57
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Re: what defines "enterprise class" hard drives?

Hi,

For SATA drives, my take is that if it has a 3YR warranty then it's a
consumer line drive. If it has a 5YR warranty from the manufacturer
then I consider it an "enterprise" class drive, even if it's not
branded as such. That being said, I think I saw some western digital
black drives with 5YR warranties (on newegg) that are not branded as
"enterprise" so they don't cost twice as much.

However, there are (or at least used to be) features of enterprise
class drives which are not available on the consumer line of drives.
Whether or not these features are necessary for operation on your
brand of storage array is something you should check. The good
companies that make storage arrays have a matrix/list of
drives+firmware versions that they've tested and qualified for use
with their arrays.

If your array is a bunch of rack servers, make sure the controllers
will accept non-branded/certified drives (e.g. make sure it doesn't
require a Dell, HP, or IBM branded drive).

After having determine that your array will take COTS components, and
if you can go with slightly slower drives, I'd go with the WD Caviar
green series, black if you want something faster. I'd stay away from
the really cheap 5400 RPM Seagate drives.

On Thu, Aug 5, 2010 at 5:33 PM, Jon Forrest <jlforrest <at> berkeley.edu> wrote:
> On 8/5/2010 2:47 PM, Rahul Nabar wrote:
>>
>> I wanted to buy some 1 Terabyte SATA drives for our storage array and
(Continue reading)

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Bruno Coutinho | 6 Aug 2010 01:28
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Re: what defines "enterprise class" hard drives?

Seagate claims that their ES.2 SATA disks have higher rotational vibration tolerance.
This could be useful if you have several disks working close to each other.


2010/8/5 Rahul Nabar <rpnabar <at> gmail.com>
On Thu, Aug 5, 2010 at 5:34 PM, Perry E. Metzger <perry <at> piermont.com> wrote:
> On Thu, 5 Aug 2010 16:47:19 -0500 Rahul Nabar <rpnabar <at> gmail.com>
> wrote:
>> I wanted to buy some 1 Terabyte SATA drives for our storage array
>> and wanted to stay away from the cheap desktop stuff. But each
>> manufacturer has some "enterprise class drives". But is there
>> something specific to look for? Most of those seem to have a MTBF of
>> around 1.2 million hours and a URE of about 1 in 10^15. The
>> S.M.A.R.T. abilities seem fairly standard.  Is there a list
>> somewhere of well tested drives? Or any recommendations?
>
> Why do you want to pay more for drives?
>
> If you have hundreds or thousands of machines, you will get failures
> no matter what, so you will need to set up your software to deal with
> failures no matter what. Assuming that a failure doesn't cause you
> much harm, you might as well simply accept a slightly higher failure
> rate in exchange for being able to pay less per node, which lets you
> buy more nodes. You can always keep spares, and indeed, you will have
> to in either case.

Sure, I do have a RAID level on it so a failure per-se isn't disaster.
And I wouldn't pay a $1000 dollar premium for it. But I wouldn't mind
paying $50 more if it translates to less trips to the cluster room and
fewer RAID rebuilds.

That's why I'm trying to buy something better than a cheap run-of-the
mill from newegg.

--
Rahul

_______________________________________________
Beowulf mailing list, Beowulf <at> beowulf.org sponsored by Penguin Computing
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf

<div>
<p>Seagate claims that their ES.2 SATA disks have <span>higher  rotational vibration tolerance</span>.<br>This could be useful if you have several disks working close to each other.<br><br><br></p>
<div class="gmail_quote">
2010/8/5 Rahul Nabar <span dir="ltr">&lt;<a href="mailto:rpnabar <at> gmail.com">rpnabar <at> gmail.com</a>&gt;</span><br><blockquote class="gmail_quote">
On Thu, Aug 5, 2010 at 5:34 PM, Perry E. Metzger &lt;<a href="mailto:perry <at> piermont.com">perry <at> piermont.com</a>&gt; wrote:<br><div class="im">&gt; On Thu, 5 Aug 2010 16:47:19 -0500 Rahul Nabar &lt;<a href="mailto:rpnabar <at> gmail.com">rpnabar <at> gmail.com</a>&gt;<br>
&gt; wrote:<br>
&gt;&gt; I wanted to buy some 1 Terabyte SATA drives for our storage array<br>
&gt;&gt; and wanted to stay away from the cheap desktop stuff. But each<br>
&gt;&gt; manufacturer has some "enterprise class drives". But is there<br>
&gt;&gt; something specific to look for? Most of those seem to have a MTBF of<br>
&gt;&gt; around 1.2 million hours and a URE of about 1 in 10^15. The<br>
&gt;&gt; S.M.A.R.T. abilities seem fairly standard. &nbsp;Is there a list<br>
&gt;&gt; somewhere of well tested drives? Or any recommendations?<br>
&gt;<br>
</div>&gt; Why do you want to pay more for drives?<br>
&gt;<br>
&gt; If you have hundreds or thousands of machines, you will get failures<br>
&gt; no matter what, so you will need to set up your software to deal with<br>
&gt; failures no matter what. Assuming that a failure doesn't cause you<br>
&gt; much harm, you might as well simply accept a slightly higher failure<br>
&gt; rate in exchange for being able to pay less per node, which lets you<br>
&gt; buy more nodes. You can always keep spares, and indeed, you will have<br>
&gt; to in either case.<br><br>
Sure, I do have a RAID level on it so a failure per-se isn't disaster.<br>
And I wouldn't pay a $1000 dollar premium for it. But I wouldn't mind<br>
paying $50 more if it translates to less trips to the cluster room and<br>
fewer RAID rebuilds.<br><br>
That's why I'm trying to buy something better than a cheap run-of-the<br>
mill from newegg.<br><div>
<div></div>
<div class="h5">
<br>
--<br>
Rahul<br><br>
_______________________________________________<br>
Beowulf mailing list, <a href="mailto:Beowulf <at> beowulf.org">Beowulf <at> beowulf.org</a> sponsored by Penguin Computing<br>
To change your subscription (digest mode or unsubscribe) visit <a href="http://www.beowulf.org/mailman/listinfo/beowulf" target="_blank">http://www.beowulf.org/mailman/listinfo/beowulf</a><br>
</div>
</div>
</blockquote>
</div>
<br>
</div>
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Joe Landman | 6 Aug 2010 01:39
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Re: what defines "enterprise class" hard drives?

On 08/05/2010 05:47 PM, Rahul Nabar wrote:
> I wanted to buy some 1 Terabyte SATA drives for our storage array and
> wanted to stay away from the cheap desktop stuff. But each
> manufacturer has some "enterprise class drives". But is there
> something specific to look for? Most of those seem to have a MTBF of
> around 1.2 million hours and a URE of about 1 in 10^15. The S.M.A.R.T.
> abilities seem fairly standard.  Is there a list somewhere of well
> tested drives? Or any recommendations?
>

Understand that these designations have more to do with product feature 
set groupings (marketing groupings) than anything else.  The feature set 
variations are mostly in the firmware for large groups of product 
offerings (lowers BOM costs by using the same physical hardware on all 
units).

A "desktop" drive will work much harder to recover an error than an 
"enterprise" drive.  The former is assumed not to be in a RAID so that 
it has to handle errors itself, and the latter is assumed to pass errors 
up to a RAID controller.

The head settling logic (not head hardware) may be different, as 
"desktop" drives, again, assumed not to be in RAIDs, shouldn't have to 
worry about all the vibration maxima at 120Hz, 166.7Hz, and 250Hz (for 
7200, 10k and 15k RPM drives), or their beat frequencies and octaves. 
"Enterprise" drives have to worry about insufficient vibration damping, 
so the firmware pack could have a different head settling/seeking code 
within it.

"Desktop" drives are assumed to not be spinning 24x7, and have some 
interesting power down capabilities, which are anathema to many RAID 
controllers (and MD RAID for that matter).

Can you use "desktop" drives in your RAIDs?  In some cases, yes.  Just 
be careful with this.

This said, I'd strongly recommend extended testing.  As we have 
discovered during some of our testing in this area, some "desktop" (and 
in this vendors case, their "enterprise") drives take ... er ... 
liberties with the specs, and can, and do wreak havoc on RAIDs (which is 
in part why we no longer ship this particular vendor's drives).

--

-- 
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics, Inc.
email: landman <at> scalableinformatics.com
web  : http://scalableinformatics.com
        http://scalableinformatics.com/jackrabbit
phone: +1 734 786 8423 x121
fax  : +1 866 888 3112
cell : +1 734 612 4615
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