Raid 5 disk rebuilding question

[grnt2121]

Hi,

Can anyone answer this question for me? This question was on my midterm and I have a feeling it will be on my final. I still haven't figured it out. Raid 5 solution uses 4 disks of 1 terabyte each. THe raid controller uses a 4-bit block data storage. During the server operation , disk drive number 3 failed. The system admin has a spare drive and will use it to recover and build the lost data on the failed disk. A snapshoot of the current data storage of the RAID array is given in the table:

///////// Drive 1 Drive 2 Drive 3 Drive 4
Stripe 1 0100 0101 - 0011
Stripe 2 0010 0000 - 0100
Stripe 3 0011 0001 - 1000
Stripe 4 0110 0001 - 1010

Show how the raid controller rebuilds the data lost in drive 3 using the spare disk. Show the 4-bit block value stored in each block per each stripe in drive # 3.

 

[tomatthe]

Lots of info if you google this one, but this seems like a pretty good summary.

http://blog.open-e.com/how-does-raid-5-work/

///////// Drive 1 Drive 2 Drive 3 Drive 4
Stripe 1 0100 0101 0010 0011
Stripe 2 0010 0000 0110 0100
Stripe 3 0011 0001 - 1000
Stripe 4 0110 0001 - 1010

I wouldn't use that as the definite correct answer, as I just read the article and tried to apply it so no promises on it being correct.