5.4 RAID

8) You want to create a software RAID 1 array on your Windows 11 workstation using Disk 1 and Disk 2. What do you need to do with Disk 1 and Disk 2 before configuring them for a RAID 1 array? - Format both disks with the same file system. - Convert the disks from basic to dynamic. - Convert the disks from dynamic to basic. - Verify that both disks are the same size.

- Convert the disks from basic to dynamic.

3) You have a computer with three hard disks. A RAID 0 volume uses space on Disk 1 and Disk 2. A RAID 1 volume uses space on Disk 2 and Disk 3. Disk 2 fails. Which of the following is true? - Data on both volumes is still accessible. - Data on both volumes is inaccessible. - Data on the RAID 1 volume is accessible. Data on the RAID 0 volume is not. - Data on the RAID 0 volume is accessible. Data on the RAID 1 volume is not.

- Data on the RAID 1 volume is accessible. Data on the RAID 0 volume is not.

9) You are configuring a new system, and you want to use a RAID 0 array for the operating system using SATA disks and a special controller card that includes a RAID processor. Which RAID method should you use? - Hardware - Software - Operating system - JBOD

- Hardware

10) You have configured Disk 3 and Disk 4 on your Windows 11 workstation as a RAID 1 array with the NTFS file system, and you have assigned F as the drive letter for the array. Each disk has an individual storage capacity of 1 TB. However, when you check the available storage size of F, you notice that it only lists 1 TB (instead of 2 TB) of available disk storage space. What should you do to resolve the issue? - Nothing. The RAID array is working as designed. - Change the volume to a spanned volume. - You need to change to a RAID 5 array. - Make sure both disks are set to dynamic instead of basic.

- Nothing. The RAID array is working as designed.

1) Jessica is concerned about losing data due to a hard disk failure. Her computer will only support a maximum of three disks. To protect her data, she has decided to use RAID (Redundant Array of Independent Disks). Which of the following RAID types would give Jessica the BEST mirrored data protection? - RAID 0 - RAID 1 - RAID 5 - RAID 10

- RAID 1

2) One of your customers wants you to build a personal server that he can use in his home. One of his concerns is making sure that he has at least one data backup stored on the server in the event that a disk fails. You have decided to back up his data using RAID. Since this server is for personal use only, the customer wants to keep costs down. Therefore, he would like to keep the number of drives to a minimum. Which of the following RAID systems would BEST meet the customer's specifications? - RAID 0 - RAID 1 - RAID 5 - RAID 10

- RAID 1

5) A computer that is being used by the HR department needs to ensure that all of the data on that computer is protected from a single hard disk failure. The data needs to be read as quickly as possible, and the HR department would like to maximize drive use as much as possible. This computer can use up to three hard drives. Which of the following RAID types would meet these requirements and provide the BEST data protection? - RAID 0 - RAID 1 - RAID 5 - RAID 10

- RAID 5

6) Which of the following drive configurations uses striping with parity for fault tolerance? - RAID 5 - RAID 1 - RAID 10 - RAID 0

- RAID 5

4) You have been asked to implement a RAID 5 solution for an engineer's desktop workstation. What is the minimum number of hard disks you can use to configure RAID 5? - Two - Three - Four - Five - Six

- Three

7) You work for a small company as the human resources specialist. Since the company is fairly small, you are maintaining all of the employee information on your desktop computer, which is running Windows 11. This computer has two high-capacity hard disks. You want to ensure that this information is protected from a hard disk failure, so you want to set up a Windows software RAID system. Which of the following would be your BEST solution? - Use mirrored volumes. - Use striped volumes. - Use spanned volumes. - Use RAID 5 volumes.

- Use mirrored volumes.

RAID 10 (stripe of mirrors)

A RAID 10 volume stripes data across mirrored pairs and across multiple disks for data redundancy. If a single disk fails, its data can be recovered using the mirrored information stored on the remaining disks. If two disks in the same mirrored pair fail, all data will be lost because there is no redundancy in the striped sets. Provides fault tolerance for a single disk failure. Provides redundancy and performance. Uses 50% of the total raw capacity of the drives due to mirroring. Requires a minimum of four disks.

RAID 5 (striping with distributed parity)

A RAID 5 volume combines disk striping across multiple disks with parity for data redundancy. Parity information is stored on each disk. If a single disk fails, its data can be recovered using the parity information stored on the remaining disks. Striping with distributed parity: - Provides fault tolerance for a single disk failure. - Provides an increase in performance for read operations. Write operations are slower with RAID 5 than with other RAID configurations because of the time required to compute and write the parity information. - Requires a minimum of three disks. - Has an overhead of one disk in the set for parity information (1 / n). --- A set with 3 disks has 33% overhead. --- A set with 4 disks has 25% overhead. --- A set with 5 disks has 20% overhead.

RAID 1 (mirroring)

A mirrored volume stores data to two (or more) duplicate disks simultaneously. If one disk fails, data is present on another disk. The system switches immediately from the failed disk to a functioning disk. Mirroring: - Provides fault tolerance for a single disk failure. - Does not increase performance. - Requires a minimum of two disks. - Has overhead. Overhead is 1 / n where n is the number of disks. If data is written twice, half of the disk space is used to store the second copy of the data. - RAID 1 is the most expensive fault tolerant system.

RAID 0 (striping)

A stripe set breaks data into units and stores the units across a series of disks by reading and writing to all disks simultaneously. Striping: - Provides an increase in performance. - Does not provide fault tolerance. A failure of one disk in the set means all data is lost. - Requires a minimum of two disks. - Has no overhead because all disk space is available for storing data.

Just a Bunch of Disks (JBOD)

Another term that is sometimes used with disk arrays is JBOD which stands for just a bunch of disks. JBOD is not a RAID configuration, but like RAID, configures multiple disks into a single logical storage unit. A JBOD configuration creates a single volume using space from two or more disks. Spanning is another term for JBOD because the volume spans multiple physical disks. Data is not striped between disks, but saved to one or more disks (depending on how the operating system decides to save each file). On a new JBOD configuration, data is typically saved to the first disk until it is full. Additional data is saved to the second disk and so on. Disks used within the spanned volume can be of different sizes. JBOD uses the entire space available on all disks for data storage (no overhead). There are no performance or fault tolerance benefits with JBOD. If one drive fails, you might be able to use disk recovery tools to recover data from the remaining disks.

Hardware RAID

Hardware RAID uses a special controller card that includes a RAID processor. Hardware RAID is the most expensive method. It provides much better performance and is more reliable than other methods.

Operating system RAID

Operating system RAID uses RAID features within the operating system. Like software RAID, the system CPU is used for RAID operations. Performance is typically better than software RAID because of integration with the operating system.

Redundant Array of Independent Disks (RAID)

Redundant Array of Independent Disks (RAID), also called Redundant Array of Inexpensive Disks, is a disk subsystem that combines multiple physical disks into a single logical storage unit. Depending on the configuration, a RAID array can improve performance, provide fault tolerance, or both. Some RAID controllers support combined levels of RAID. For example, RAID 0+1 is a striped array that is mirrored. Other combined configurations that might be supported include RAID 1+0 (also called RAID 10), RAID 5+0, and RAID 5+1. While some RAID configurations provide fault tolerance in the event of a disk failure, configuring RAID is not a substitute for regular backups.

Software RAID

Software RAID uses a driver and the system CPU for controlling RAID operations. This is the slowest form of RAID. Some RAID controller cards support RAID configuration, but without the onboard RAID processor. These solutions are classified as software RAID (sometimes called fake RAID) even though you install a controller card to provide RAID capabilities. Many motherboards include built-in (onboard) support for RAID. RAID implemented in this way is typically software/driver RAID.

For all RAID configurations, the amount of disk space used on each disk must be

of equal size. If disks in the array are of different sizes, the resulting volume will be limited to the smallest disk. Remaining space on other drives can be used in other RAID sets or as traditional storage.