Chad Van Buren Jr
Unit 2 Assignment 1: Disk Redundancy Research

1. RAID stands for redundant array of independent discs 2. We would use RAID depending on the need of the individual or entity. RAID differs depending on the type you install. In question 3, I will discuss the difference between RAID types. From there you can decide which one suits your needs best.
3a. RAID 0- Is taking any number of disks and striping data across all of them. This will greatly increase speeds, as you're reading and writing from multiple disks at a time. An individual file can then use the speed and capacity of all the drives of the array. The downside to RAID 0 is that it is not redundant; the loss of any individual disk will cause complete data loss.
b. RAID 1- Requires at least 2 hard drives. These disks mirror each other, meaning that all the data saved on one will then be mirrored or copied onto the other. The advantage to this RAID is that if one of your hard drives fails, you can then manually plug in your other hard drive to make it the primary and continue on with your business without delay or loss of data. If your second disk is then not replaced and the secondary hard drive fails all your data will be lost.
c. RAID 5- This RAID requires the use of at least 3 hard drives. It’s similar to RAID 0 in the sense that data is stripped through all the hard drives to increase performance. What makes this RAID unique is the use of what’s known as parity bit. What this does is create a space on the hard drive that can be read as odd or even, in this case 1 or 0. If a hard drive fails, data will not be lost and operations can still be continued as normal.
d. RAID 6- Requires the use of at least 4 hard drives. This RAID can be referred to as the double parity RAID. Meaning this that 2 parity stripes are used on each disk. It allows for two disk failures within the RAID set before any data is lost. It allows for two disk failures within the RAID set before any data is lost.
4. The only use for RAID 0 is to increase cache speed and performance with no regard to loss of data.
5. I do not think RAID 1 is the most expensive out of the listed RAIDs in this assignment. Generally it’s used with only a pair of disks, so the cost of the additional hard drive will determine how expensive this RAID will be. Individuals would utilize this RAID in home or business environments for the redundancy benefit. A hard drive can fail and you could still maintain operation in a timely manner without loss of any data. It also increases performance, but write time is also increased due to data being writ on both disks.
6. If I had a choice of RAID to use in my home environment without factoring in the cost, I would choose RAID 10. RAID 10 requires at least 4 drives and is a combination of RAID 1 and RAID 0 getting you both increased speed and redundancy. In a four drive configuration, two mirrored drives hold half of the striped data and another two mirror the other half of the data. This means you can lose any single drive, and then possibly even a second drive without losing any data. Just like RAID 1, you'll only have the capacity of half the drives, but you will see improved read and write performance and also have the fast rebuild time of RAID 1.
7. The difference between software and hardware RAIDS is simple. Software is a downloadable program that will utilize what hardware you already have and configure it into a RAID. Where hardware is needed to be purchased and physically installed. Both have pros and cons, typically hardware are the best option to go with. http://www.differencebetween.net/technology/difference-between-hardware-raid-and-software-raid/ http://searchstorage.techtarget.com/definition/RAID-6-redundant-array-of-independent-disks
http://www.steadfast.net/blog/index.php/servers/almost-everything-you-need-to-know-about-raid