...Redundant Array of Independent Disk (RAID) is a method of storing the same data in different places on multiple disks. Disk storage space is partitioned to units this technique is called disk striping. Storing the data on multiple disks improves the performance because the operations are done and overlapped in balanced way. Storing data redundantly on multiple disks increases fault tolerance. Data that are stored in multiple disk and they are accessed parallel to achieve. * Large data access by higher data transfer rates. * Small data access by higher I/O rates Some of the different types of RAIDs are discussed below. RAID Level 0: This has non redundant disk array and less cost to the organization because it does not have redundancy at all. It is thought that this has better performance; it does not have to update redundant information. But it does not, redundancy can perform better by scheduling request in the disk by selectively with shortest seek and rotational delays. If there is no redundancy data will be loss with single disk failure. RAID Level 1: This uses the solution called mirroring and uses many disk that non redundant array disk. Whenever data is written to the disk it is also written other redundant disk it has always copies of two, so data is not lost because of single disk failure it can always request for other copies. RAID Level 2: This is memory style and provides less cost for the failed component than mirroring...
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...RAID stands for Redundant Array of Independent Disks. It is a storage technology that combines multiple drive components into a logical unit. Data is distributed across the drives, depending on the level of performance and redundancy required, in one of several RAID levels. We use RAID when liability and data redundancy are important to you. Even if you take backups, you will need to take the time to restore those backups and those backups could be hours or days old, resulting in data loss. RAID allows you to survive a drive loss without data loss and in many cases without any downtime. RAID is also useful if you are having disk IO issues, where applications are waiting on the disk to perform tasks. Going with RAID will provide you additional throughput by allowing you to read and write data from multiple drives instead of a single drive. There are many types of RAID to choose from depending on what you are looking for. RAID 0 provides improved performance and additional storage but has no redundancy. In RAID 1data is written to two drives producing a mirrored set. This means that the read request is serviced by either of the drives, which contains the data requested. The drive has the least amount of seek time is used. RAID 5 distributes parity along with the data and requires all drives but only needs one to be present to operate. RAID 5 requires at least three disks. This way the array is not destroyed by a single drive failure, and maintains the data. RAID 6 provides fault...
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...Unit 2 Assignment 1 Disk Redundancy Research 1. What Does RAID stand for? Redundant Array of Independent Disks 2. When would we use RAID? It’s a balanced way to improve overall storage performance. 3. Define the following types of RAID a. RAID 0: Provides data striping but it lacks both fault tolerance and redundancy to improve performance as a result if one drive fails then all data in the array is lost. b. RAID 1: Provides disk mirroring and duplexing so level one provides twice the read transaction rate of single disks and the same write transaction rate as a single disk. c. RAID 5: Uses block-level striping with parity data distributed across all member disks. Also RAID 5 has achieved popularity because of its low cost of redundancy. d. RAID 6: Extends RAID 5 by adding an additional parity block thus it uses block-level striping with two parity blocks distributed across all member disks. RAID 6 does not have a performance penalty for read operations but it does have a performance penalty on write operations because of the overhead associated with parity calculations and it’s also no less space efficient then RAID 5. 4. Why is RAID 0 of any use if it offers no redundancy? Because it provides data striping even though it lacks both fault tolerance and redundancy. 5. Why do you think that RAID 1 can be the most expensive? You get two copies of everything after you have a hard drive fail on you with all of the data completely lost you’ll understand that spending...
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...Abstract Redundant Array of Independent Disks, universally known as RAID is a subsystem for disks by definition and as first coined in the year 1987 by David, Garth and Randy Katz at the University of California. Initially RAID was created to combine a number of cheaper drives in order to provide high capacity. However today RAID is designed for providing one of the most important, essential and looked-for feature in any system i.e. “fault tolerance” or “failover protection”. Fault tolerance increases the overall efficiency and reliability of the system. This short paper provides a pragmatic overview of RAID in general, the two methods used in RAID to enhance its reliability and performance, pros and cons associated with RAID and a contrast of RAID level 1 and RAID level 5 schemas on the basis of read and write actions. Introduction RAID has a different drive just for replacing the drive that has crashed. This spare drive is called hot spare. This drive can be compared to a spare part that is used during emergency. This spare drive must always be ready and the replacement of the failed part (drive) should be done straightaway. After replacing the failed drive with the hot spare drive it is required that the entire system knows that the spare drive is being used. In addition we should also take a backup of all the data, just in case the spare drive also fails. However, RAID rules the technology used in implantation of secure systems. Physical and logical arrays and disks...
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...does RAID stand for? Redundancy Array of Inexpensive (or independent) Disks. 2. When would we use RAID? If reliability and data redundancy is important to you, if you take backups you will need to restore those backups and those backups can be hours or days old, resulting in data loss. RAID allows you to survive a drive loss without data loss and in many cases without any downtime. It is also useful if you’re having disk IO issues, where applications are waiting on the disk to perform tasks. Allows you to read and write data from multiple drives. The hardware RAID card will include additional memory to be used as cache, reducing the strain put on the physical hardware and increase overall performance. 3. Define the following types of RAID a) RAID 0- (Striping) Taking any number of disks and striping data across all of them. Greatly increases speeds, as your reading and writing multiple disks at a time. Offers no redundancy but can be used for cache and other purposes where speed and reliability/data loss does not matter. b) RAID 1- (Mirroring) generally used with a pair of disks, though could be done with more, and would identically mirror/copy the data equally across all the drives in the array. The point of RAID 1 is primarily for redundancy, as you can completely lose a drive, but still stay up and running off the additional drive(s). c) RAID 5- (striping/distributive Parity) Requires the use of at least three drives. And will take the idea of RAID 0,...
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...Data Protection Proposal Lake Medical Hospital By: Frank Angelone 05/31/14 Lake Medical Services in this proposal I will inform you of the options. The Standard for using data protection is by using RAID. RAID stands for Redundancy Array of Independent Disks. What this system allows you to do from an owner’s perspective, is to store and process all of your network needs. Considering you are a hospital you need to protect your patient’s information. With this data protection system it will allow you to collect large amounts of data by combining hard drives into one. What the RAID system does is take many hard drives and appear in your network as one. There are three main standards of RAID. First is R.A.I.D. 0, second is R.A.I.D 1, and third is R.A.I.D. There is a fourth option we will discuss that I am proposing for you to use. If you would like another option this can be discussed, but first we will discuss the three main standards. First option of R.A.I.D. is 0. When using option 0 you need to have at least 2 hard drives. You may use more drives than to increase the speed of your network (Iomega, 2009). Also looking at the size of the network will determine how many drives will be needed to run the system. This option uses a method called striping (Iomega, 2009). Striping is when the data that is stored on the drive is spread across the disks on the drives. What this means is that every piece of data is split up into small segments...
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...RAID Explained RAID used to stand for "redundant array of inexpensive disks". Today the term has been updated to "redundant array of independent disks". RAID is a way of grouping individual physical drives together to form one bigger drive called a "RAID set". RAID can make many smaller disks appear as one large disk to a server. The RAID set represents all the smaller physical drives as one logical disk to your server. The logical disk is called a LUN, or "logical unit number". Using RAID has two main advantages. Better performance and higher availability, which means it goes faster and breaks down less often. RAID benefits explained Performance is increased because the server has more "spindles" to read from or write to when data is accessed from a drive. Availability is increased because the RAID controller can recreate lost data from parity information. What is parity? Parity is basically a checksum of the data that was written to the disks, which gets written along with the original data. RAID can be done in software on a host, or in hardware on the storage controllers. The server accessing the data on a hardware-based RAID set never knows that one of the drives in the RAID set went bad. The controller recreates the data that was lost when the drive went bad, by using the parity information stored on the surviving disks in the RAID set. There are a number of different ways drives can be grouped together to form RAID sets. The different methods used to group drives are...
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...RAID Explained RAID used to stand for "redundant array of inexpensive disks". Today the term has been updated to "redundant array of independent disks". RAID is a way of grouping individual physical drives together to form one bigger drive called a "RAID set". RAID can make many smaller disks appear as one large disk to a server. The RAID set represents all the smaller physical drives as one logical disk to your server. The logical disk is called a LUN, or "logical unit number". Using RAID has two main advantages. Better performance and higher availability, which means it goes faster and breaks down less often. RAID benefits explained Performance is increased because the server has more "spindles" to read from or write to when data is accessed from a drive. Availability is increased because the RAID controller can recreate lost data from parity information. What is parity? Parity is basically a checksum of the data that was written to the disks, which gets written along with the original data. RAID can be done in software on a host, or in hardware on the storage controllers. The server accessing the data on a hardware-based RAID set never knows that one of the drives in the RAID set went bad. The controller recreates the data that was lost when the drive went bad, by using the parity information stored on the surviving disks in the RAID set. There are a number of different ways drives can be grouped together to form RAID sets. The different methods used to group drives are...
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...RELIABILITY and PERFORMANCE Through RAID Structures Casundra Gilder Southern New Hampshire University July 18, 2013 Abstract Redundant Arrays of Independent Disks (RAIDs) are used to address performance and reliability of disks. RAIDs are just a large number of inexpensive disks that can be linked together to create one single large storage space that offers better performance, reliability and storage capacity for older systems. RAIDs have become more popular over the years and increasing common with end user systems. There are many levels of RAIDs that are in existence today. With the creation of RAIDs, more computer systems have become better as far as increased performance and redundancy. Redundancy is one of the most important factors when it comes to developing RAIDs for server environments. When a drive fails on a system, a user can either change the old drive for a new one without having to power down the system or a RAID could be used. All redundancy methods depend on the version of RAID used. Performance of a system will depend on the number of drives used in the array and the controllers and increased performance can only be located when specific versions of RAIDs are used. There is a limit to the rate at which data can be read from or written to a hard disk platter. By implementing a RAID, a single disk will have increased performance when it comes to reading and writing to multiple disks at the same time. RAIDs handle hard disk drive failures in...
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...01/28/2016 Unit 6 Assignment 1: Video summary 4 (RAID) 1. URL Of video. https://www.youtube.com/watch?v=eE7Bfw9lFfs 2. Summary of video. In this video we learn the meaning of raid, what it does, and how to efficiently configure raid arrays. RAID stands for Redundant Array of Independent Disks. The three most common types of RAID; RAID 0, RAID 1, and RAID 10. Different raid configurations offer different advantages, like speed and reliability. RAID 0 is all about speed, by striping the data across 2 drives you can keep all of the capacity and double the read and write performance. However, RAID 0 provides no reliability, if one of your drives fail you will all of your data. RAID 1 in the other hand provides maximum reliability, but no performance increase. When both performance and reliability are needed, there is the option for a RAID 10 configuration. To configure a RAID 10 array, you need four drives, stripe the data on all four drives and mirror two against two. This RAID configuration allows you to get about double the performance and capacity of an individual drive, and you can lose up two drives without losing any data. 3. 3 topics mentioned in the video. * The meaning of RAID * Pros and cons of RAID configurations * How to configure RAID 4. 3 terms used in the video and their definitions. * Data striping: The technique of segmenting logically sequential data, such as a file. * RAID: Data storage virtualization technology that combines...
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...December 7th, 1941 the United States was attacked at Pearl Harbor by Japanese forces. American forces already stationed in the Philippines as a deterrent against a Japanese invasion of the islands, were attacked by the Japanese hours after Pearl Harbor. With more than 72,000 American and Filipino soldiers fighting with outdated weapons, lacking supplies, stricken with disease and malnourishment were forced to lay down their arms to the Japanese on April 9th, 1942. This was due to the promise of reinforcements after General MacArthur and a few select officers evacuated the island on orders from the president. The Japanese however had only accommodated for 10,000 to 25,000 thousand POWs and the Us and Philippine soldiers were forced to march 60 miles to the Cabanatuan and Bataan prison camps. On October 20th, 1944 General Douglas MacArthur’s forces landed on Leyte, as Americans prepared for the main invasion of Luzon the Japanese captors continued to execute their prisoners. Several plans were submitted for possible rescue attempts of the prisoners but most fell through simply due to logistics or possible traders amongst the ranks of the Philippine guerillas. On January 26th, 1945 major Bob Lapham, the American US Army Forces Far East senior guerrilla chief and another guerilla leader Juan Pojota, traveled from his location near the prison camp to the Sixth Army headquarters. Lapham proposed to Lieutenant General Walter Krueger’s intelligence Chief Colonel Horton White that a rescue...
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...does RAID stand for? RAID stands for Redundant Array of Inexpensive Drives. That is the original term. The latest is Redundant Array of Independent Disks. 1 2. When would we use RAID? RAID is used as enhanced storage space, storing the same data in different places. Thus redundancy. 2 3. Define the types of RAID’s? a) RAID 0: This technique uses the Striping technique but has no redundancy. It has no fault tolerance. It offers very good performance though. Good for a backup. RAID 0 can be on home computers.2,3 b) RAID 1: This RAID uses Disk Mirroring. It also uses 2 drives that duplicate the storage of data. There’s no striping. The read performance has been improved since either disk can be read. RAID 1 gives the best performance and fault tolerance. It can be on home computers. 2,3 c) RAID 5: This RAID stores Parity information, but not redundant data. It has a rotating Parity Array, addressing the write limitation in RAID 4. It uses 3 sometimes 5 disks for the array. This RAID is best used for multi-user systems in which performance is not critical. Parity is used to protect the data, so if one hard drive dies, the information that was on that particular drive will be on at least another drive.2,3 d) RAID 6: This RAID is similar to RAID 5, but includes a second Parity Scheme that’s distributed across different drives giving high fault and drive failure tolerance.3 4. Why is RAID 0 of any use if it offers no redundancy? RAID 0 works something like a RAID 5 but...
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...1. What does RAID stand for? Redundant Array of Independent Disks. Source: Steadfast.com 2. When would use RAID? When experiencing disk IO issues, where applications are waiting on the disk to perform tasks. It also provides additional throughput by allowing you to read and write data from multiple drives instead a single drive. Source: Steadfast.com 3. Define the following types of RAID: RAID 0 (Striping) - 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 though is that it is NOT redundant, the loss of any individual disk will cause complete data loss. I would not recommend ever using RAID 0 in a server environment. You can use it for cache or other purposes where speed is important and reliability/data loss does not matter at all, but it should not be used for anything other than that. As an example, with the 5% annual failure rate of drives, if you have a 6 disk RAID 0 array you've increased your risk of data loss to nearly 27%. RAID 1 (Mirroring) - RAID 1 is generally used with a pair of disks, though could be done with more, and would identically mirror/copy the data equally across all the drives in the array. The point of RAID 1 is primarily for redundancy, as you can completely lose a drive, but still stay up and running off the...
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...UNIT 2 ASSIGNMENT 1 2 1. What does RAID stand for? Originally, RAID stood for Redundant Array of Inexpensive Disks. Currently it is more commonly known as standing for Redundant Array of Independent Disks. 2. When would you use RAID? Having data on multiple disks helps ensure against data loss in case of a drive failure. If one of the drives fails most levels of RAID allow the user to just replace that one drive while not losing any data. Having multiple drives also allows multiple read and write operations to be going on at the same time, which increases performance. 3. Define the following types of RAID: a. RAID 0 Using two or more disks, RAID 0 utilizes a striped disk array with data broken down and written part to each disk. This increases performance since multiple input / output operations can be carried out at the same time. RAID 0, unlike the other levels of RAID, does not provide any protection against data loss. If one drive goes down, all of the data will be corrupted. b. RAID 1 RAID 1 requires two or more disks to operate, it organizes data into mirrored pairs. When data is written to one of the drives in a mirrored pair, it is automatically written to both drives. That way if one of the two drives fails the user just needs to replace that one drive. It also provides an increase in performance since two read operations can be performed at the same time. Only one write can be performed at a time since the data must be written to...
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...1. What does RAID stand for? Short for redundant array of independent or (inexpensive) disks. It’s a category of disk drives that employ two or more drives in combination for fault tolerance performance. http://www.webopedia.com/TERM/R/RAID.html 2. When would you use RAID? When trying to survive a drive loss without data loss and in many cases without any downtime. http://steadfast.net/blog/index.php/general/almost-everything-you-need-to-know-about-raid 3. Define the following types of RAID: a. RAID 0- (known as a stripe or striped volume) splits data evenly across two or more disks (striped) without parity information for speed. http://en.wikipedia.org/wiki/Standard_RAID_levels b. RAID 1- an exact copy (or mirror) of a set of data on two disks. http://en.wikipedia.org/wiki/Standard_RAID_levels c. RAID 5- (block-level striping with distributed parity) distributes parity along with the data and requires that all devices but one be present to operate. https://en.wikipedia.org/wiki/RAID#RAID_5 d. RAID 6- (block-level striping with double distributed parity) provides a fault tolerance up to two failed drives. https://en.wikipedia.org/wiki/RAID#RAID_6 4. Why is RAID 0 of any use if it offers no redundancy? It can be used to improve performance through concurrent access and/or create large logical disks out of multiple physical disks. 5. Why do you think that RAID 1 can be the most expensive? Why would people utilize it if it’s so costly? Raid 1 is the most expensive...
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