Redundancy Strategies and RAID - CompTIA Security+ Performance Based Question

The Cyberkraft Security+ Bootcamp will fully prepare you to ace the Security+ exam with 40 hours of live training with our CompTIA certified instructors:
Ace your exam and earn an average yearly salary of $85,000.
Save $200 off of your enrollment with discount code: YouTube
Our bootcamp includes:
• 40 hours of live instruction over five days of instruction
• Exam fee included ($381 value)
• Expert instruction in all five domains
• Access to the Official CompTIA Security+ Learn and Labs Environment with PBQs, Labs, a digital textbook, and more
• Over 1000 pages of PDF study guides
• 12 practice tests and 6 simulation exams (500+ total questions) to fully prepare you for test day
• High definition video lessons accessible online or through the Cyberkraft App (included)
• Weekly study sessions and live support
• Lifetime access to all future course updates
• Second Shot Guarantee – If you don’t pass the first attempt, we will pay for your second exam

Sign up for our Security+ Complete Self-Paced Course to study for and ace the exam on your own schedule:
For 10% off your enrollment use discount code: YouTubeSP

Cyberkraft is a CompTIA Authorized Partner.

[AaronRodi]

"Radio Selectors" are referring to the "yes and no" options under which raid configuration to use to protect data. It's a term used in web developments.

[natalynndawn]

Thank you, you have been so helpful, I am so happy I stumbled upon your videos my exam is in 15 days and been spinning my wheels a bit on key areas.

[endcensorship]

Most people don't know that when you do a multiple choice test, "radio selector" is the term for the bubble you fill in on the test. This is a poorly worded question, in my opinion, because you shouldn't compose questions that have terms not known to the general population. If you make tests all day long, and you compose test questions, then "radio selector" is a term you will use as a professional all the time. The test composer should use "choose the bubble" or something like that.

[jesseholliday]

I jave seen a lot of questions in the past involvinf RAID 0 also, full stripping with no mirroring

[Cornstar]

The RAID 5 question and the 'correct' answer seem nonsensical to me. If any two disks fail, you still have Bit 1 and Bit 2 on the one remaining disk with an unnecessary parity bit. How is this not just triple mirroring like the RAID 1 image above with a useless parity bit on each disk (notice that it's exactly the same with just one parity bit added to each disk)?

Here's how the setup should look like for RAID 5:

Disk 0:
Row 1: Bit 1
Row 2: Bit 3
Row 3: Parity Bit (for 5 & 6)
Disk 1:
Row 1: Bit 2
Row 2: Parity Bit (for 3 & 4)
Row 3: Bit 5
Disk 2:
Row 1: Parity Bit (for 1 & 2)
Row 2: Bit 4
Row 3: Bit 6

With this setup:

If Disk 0 fails, you can recover:

Bit 1 using the parity on Disk 2 (Row 1) and Bit 2 on Disk 1.
Bit 3 using the parity on Disk 1 (Row 2) and Bit 4 on Disk 2.
The parity of Bit 5 & 6 isn't needed for recovery in this scenario.

If Disk 1 fails, you can recover:

Bit 2 using the parity on Disk 2 (Row 1) and Bit 1 on Disk 0.
Bit 5 using the parity on Disk 0 (Row 3) and Bit 6 on Disk 2.
The parity of Bit 3 & 4 isn't needed for recovery in this scenario.

If Disk 2 fails, you can recover:

Bit 4 using the parity on Disk 1 (Row 2) and Bit 3 on Disk 0.
Bit 6 using the parity on Disk 0 (Row 3) and Bit 5 on Disk 1.
The parity of Bit 1 & 2 isn't needed for recovery in this scenario.

This demonstrates how only one disk can fail. In the CompTIA question, two disks can fail which is not typical of a three disk RAID 5 setup.

[m.hussien]

in raid 5 disk 2, is there a particular order of choosing Bit order?

[tawm]

The RAID 1 entry in the All-In-One Sec+ book says, "...copies the data from one disk onto two or more disks. If any one disk is lost, the data is not lost since it is also copied onto the other disk(s)." (Pg. 209)

That is a weird way to phrase it to me. It seems to imply that you have your actual storage disk and then two additional backups? I assume they just mean your storage disk and a backup is RAID 1....maybe.

Or is it more typical at the enterprise level to maintain more than one backup copy of things - it would make some sense.