MESSAGE
| DATE | 2014-12-06 |
| FROM | Maneesh Kongara
|
| SUBJECT | Re: [LIU Comp Sci] Parity Bit Algebra
|
From owner-learn-outgoing-at-mrbrklyn.com Sat Dec 6 21:50:06 2014
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From: Maneesh Kongara
Date: Sun, 07 Dec 2014 02:50:04 +0000
Message-ID:
Subject: Re: [LIU Comp Sci] Parity Bit Algebra
To: learn-at-mrbrklyn.com
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Have you seen the review questions?
On Sat, Dec 6, 2014, 9:49 PM Ruben Safir wrote:
>
>
> I can't even read the question
>
>
>
> On 12/07/2014 02:38 AM, Maneesh Kongara wrote:
> > I've finished all other questions... I'm breaking my head with the last
> > question.
> > On Dec 6, 2014 9:36 PM, "Ruben Safir" wrote:
> >
> >> On 12/06/2014 11:09 PM, Maneesh Kongara wrote:
> >>> Preliminary work as in answers to the other questions of the
> assignment?
> >>> On Dec 6, 2014 6:08 PM, "Ruben Safir" wrote:
> >> I'm going to crash, how far did you get in the assingment.
> >>
> >> Call me is 20 minutes. I have one hour to do it :)
> >>
> >>
> >>>> On 12/06/2014 10:52 PM, Maneesh Kongara wrote:
> >>>>> Thanks so much for sharing Mr Rubin. Have you completed the
> assignment?
> >>>>> On Dec 6, 2014 5:49 PM, "Ruben Safir" wrote:
> >>>> Not even looked at it outside of the library. I'm burning up trying
> to
> >>>> catch up. Do you have some preliminary work?
> >>>>
> >>>> I did give it throught. Part of the solution must have to do with the
> >>>> Comp + 2 binary
> >>>>
> >>>> I can't even find my notes...
> >>>>
> >>>>>> This is from theidiscussion of Raid 3 Stallings Text which the slide
> >>>>>> come from. It is related to the problem you asked about the parity
> >> bit
> >>>>>> calculation for the Hamming Code
> >>>>>>
> >>>>>> Not the methodology for logical calculation, it is straight math
> >>>>>>
> >>>>>> Note that X is XOR for whatever UFT reason
> >>>>>>
> >>>>>>
> >>>>>> REDUNDANCY In the event of a drive failure, the parity drive is
> >> accessed
> >>>>>> and data is reconstructed from the remaining devices. Once the
> failed
> >>>>>> drive is replaced, the missing data can be restored on the new drive
> >> and
> >>>>>> operation resumed.
> >>>>>>
> >>>>>> Data reconstruction is simple. Consider an array of five drives in
> >> which
> >>>>>> X0 through X3 contain data and X4 is the parity disk.The parity for
> >> the
> >>>>>> ith bit is calculated as follows:
> >>>>>>
> >>>>>> X4(i) = X3(i) { X2(i) { X1(i) { X0(i)
> >>>>>>
> >>>>>> where { is exclusive-OR function.
> >>>>>>
> >>>>>> Suppose that drive X1 has failed. If we add X4(i) { X1(i) to both
> >> sides
> >>>>>> of the preceding equation, we get
> >>>>>>
> >>>>>> X1(i) = X4(i) { X3(i) { X2(i) { X0(i)
> >>>>>>
> >>>>>>
> >>>>>> file:///home/ruben/william stallings - computer organization and
> >>>>>> architecture designing for performance (8th edition).pdf
> >>>>>>
> >>>>>> Page 202
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> http://www.nylxs.com/images/raid3_parity_math.png
> >>>>>>
> >>>>>> Ruben
> >>>>>>
> >>
>
>
--001a11c11b50fe6d3c0509975d80
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Have you seen the review questions?
On Sa= t, Dec 6, 2014, 9:49 PM=C2=A0Ruben Safir < ix.com">mrbrklyn-at-panix.com> wrote: te" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"=
>
I can't even read the question
On 12/07/2014 02:38 AM, Maneesh Kongara wrote:
> I've finished all other questions... I'm breaking my head with=
the last
> question.
> On Dec 6, 2014 9:36 PM, "Ruben Safir" <mrbrklyn-at-panix.com" target=3D"_blank">mrbrklyn-at-panix.com> wrote:
>
>> On 12/06/2014 11:09 PM, Maneesh Kongara wrote:
>>> Preliminary work as in answers to the other questions of the a=
ssignment?
>>> On Dec 6, 2014 6:08 PM, "Ruben Safir" <"mailto:mrbrklyn-at-panix.com" target=3D"_blank">mrbrklyn-at-panix.com> wr=
ote:
>> I'm going to crash, how far did you get in the assingment.
>>
>> Call me is 20 minutes.=C2=A0 I have one hour to do it :)
>>
>>
>>>> On 12/06/2014 10:52 PM, Maneesh Kongara wrote:
>>>>> Thanks so much for sharing Mr Rubin. Have you complete=
d the assignment?
>>>>> On Dec 6, 2014 5:49 PM, "Ruben Safir" < href=3D"mailto:mrbrklyn-at-panix.com" target=3D"_blank">mrbrklyn-at-panix.com>> wrote:
>>>> Not even looked at it outside of the library.=C2=A0 I'=
m burning up trying to
>>>> catch up.=C2=A0 Do you have some preliminary work?
>>>>
>>>> I did give it throught.=C2=A0 Part of the solution must ha=
ve to do with the
>>>> Comp + 2 binary
>>>>
>>>> I can't even find my notes...
>>>>
>>>>>> This is from theidiscussion of Raid 3 Stallings Te=
xt which the slide
>>>>>> come from.=C2=A0 It is related to the problem you =
asked about the parity
>> bit
>>>>>> calculation for the Hamming Code
>>>>>>
>>>>>> Not the methodology for logical calculation, it is=
straight math
>>>>>>
>>>>>> Note that X is XOR for whatever UFT reason
>>>>>>
>>>>>>
>>>>>> REDUNDANCY In the event of a drive failure, the pa=
rity drive is
>> accessed
>>>>>> and data is reconstructed from the remaining devic=
es. Once the failed
>>>>>> drive is replaced, the missing data can be restore=
d on the new drive
>> and
>>>>>> operation resumed.
>>>>>>
>>>>>> Data reconstruction is simple. Consider an array o=
f five drives in
>> which
>>>>>> X0 through X3 contain data and X4 is the parity di=
sk.The parity for
>> the
>>>>>> ith bit is calculated as follows:
>>>>>>
>>>>>> X4(i) =3D X3(i) { X2(i) { X1(i) { X0(i)
>>>>>>
>>>>>> where { is exclusive-OR function.
>>>>>>
>>>>>> Suppose that drive X1 has failed. If we add X4(i) =
{ X1(i) to both
>> sides
>>>>>> of the preceding equation, we get
>>>>>>
>>>>>> X1(i) =3D X4(i) { X3(i) { X2(i) { X0(i)
>>>>>>
>>>>>>
>>>>>> file:///home/ruben/william stallings - computer or=
ganization and
>>>>>> architecture designing for performance (8th editio=
n).pdf
>>>>>>
>>>>>> Page 202
>>>>>>
>>>>>>
>>>>>>
>>>>>> y_math.png" target=3D"_blank">http://www.nylxs.com/images/raid3_pari=
ty_math.png
>>>>>>
>>>>>> Ruben
>>>>>>
>>
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