Lab46 Wiki

• RAID stands for redundant array of independent disks and is a storage technology that will combine multiple disk drives into one logical unit. Once the drives are combined into a logical unit any data is stored across the drives in various different ways know as “RAID levels” and will depend on the level of redundancy and/or performance the user wants.

• RAID 0 is used for performance and combing all disks into one logical drive with the storage capacity of all disks combined but has no redundancy. It requires a minimum of two disks and the disks will be striped. By striping your data you can can write X amount of times faster, where X is the amount of drives. If you have one drive and want to write two blocks of data you have to write the first block then the next. If you have two striped drives and want to write two blocks of data, you can write the first block to the first drive and the second block to the second drive thus doubling your performance.

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• RAID 1 Gives redundancy but does not increase performance nor gives you a larger logical drive. RAID 0 stripes but RAID 1 mirrors. It requires a minimum of 2 disks and everything that is written to one disk is mirror on all other disks.

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• RAID 5 gives good performance as blocks are striped and good redundancy by using parity. Parity is not as efficient as mirroring. You need a minimum of 3 disks. In a 3 disk system with all disks of equal size, your logical drive would be double the size of your drives as the the third portion would be used for parity data. This gives you the most cost effective way to increase performance and have redundancy with the least amount of drives.

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• RAID 10 is a combination of RAID 0 and RAID 1. It is a stripe of mirrors and requires a minimum of 4 disks. In a four disk system where all disks are the same size, you will double your size. This gives you the greatest performance and redundancy. If you have two blocks of data, the first block and second block are written simultaneously to multiple drives, increasing performance and giving you a backup copy.

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• Semiconductor memory uses semiconductor-based integrated circuits to store information. Both volatile and non-volatile forms of semiconductor memory exist. Most computers today use dynamic volatile semiconductor memory or dynamic random access memory(DRAM) as their primary storage. Flash memory is an example of non-volatile semiconductor memory as well as offline storage. Solid state drives are also non-volatile semiconductor memory but secondary storage.

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• Magnetic storage is non volatile and uses different patterns of magnetization on a magnetically coated surface to store information . Floppy disks and hard drives are examples of Magnetic storage. Floppy disks are still used, albeit rarely, and are a form of offline storage. Hard disks are an example of secondary storage.

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• Optical storage is non volatile and stores information in deformities on the surface of a circular disc and reads this information by illuminating the surface with a lasers. The deformities may be permanent (read only media ), formed once (write once media) or reversible (recordable or read/write media). CD and DVD's are examples of read only optical storage, CD-R, DVD-R are examples of write once optical storage, and CD-RW, DVD-RW are examples or read/write optical storage.

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State the course objective

In your own words, define what that objective entails.

State the method you will use for measuring successful academic/intellectual achievement of this objective.

Follow your method and obtain a measurement. Document the results here.

Reflect upon your results of the measurement to ascertain your achievement of the particular course objective.

• How did you do?
• Is there room for improvement?
• Could the measurement process be enhanced to be more effective?
• Do you think this enhancement would be efficient to employ?
• Could the course objective be altered to be more applicable? How would you alter it?