PPT-RAID (Redundant Arrays of Independent Disks)

RAID Redundant Arrays of Independent Disks Disk organization technique that manages a large number of disks providing a view of a single disk of High capacity and high speed up using multiple disk in parallel. How are PCR Arrays Utilized The RT57522 Profiler PCR Arrays have been increasingly used in research on cancer immunology stem cells toxicology biomarker discovery and validation and phenotypic analysis of cells and transgenic animals Why PCR Arrays Clare O’Brien . WWII in the Pacific . The Main Players. Vice Admiral Halsey of the . U.S.S. Enterprise . Lieutenant Colonel . James Doolittle . Captain Marc Mitscher of the . U.S.S. Hornet. In response to the shock and anger following Pearl Harbor. Fourie Joubert. Physical Storage. Physical disks may be inside the server, or in an external enclosure. The server may also be connected to storage in other ways, such as on a network. The physical disks may have platters, or be SSD. RAID. What is RAID. ?. RAID is an acronym for Redundant Array of Independent Drives (or Disks), also known as Redundant Array of Inexpensive Drives (or Disks). The various types of RAID are data storage schemes that divide and/or replicate data among multiple hard drives. . . We . have all heard someone say something like this: . "It was an unexpected surprise when a pair of baby twins was born at 12 midnight.". What is a surprise if not unexpected? What are twins if not a pair? Who can be born but a baby? When is midnight if not at 12? The expressions we use are full of redundancy. Your friend could just as well have said: . Lecture 39: IO Disks. Instructor: Dan Garcia. http://inst.eecs.Berkeley.edu/~cs61c/. 1. Technology in the News. www.cnn.com/2014/04/28/tech/innovation/google-self-driving-car/. 2. Review. . Exceptions are “Unexpected” events. Case Study: Facebook f4. Steve Ko. Computer Sciences and Engineering. University at Buffalo. Recap. Engineering principle. Make the common case fast, and rare cases correct. Power law. Haystack. A design for warm photos. Denny Cherry. mrdenny@mrdenny.com. twitter.com/. mrdenny. About Me. Author or Coauthor of 4 books. 6+ SQL Mag articles. Dozens of other articles. Microsoft MVP since Oct 2008. Microsoft Certified Master. and RAID. Outline. Disks. Disk scheduling algorithms. Redundancy in storage . systems, RAID. 2. Disk Geometry. Disks have multiple platters. Each platter has . an arm and a head for accessing data. The arms for the different platters move together. “Redundant Array of Inexpensive Disks”. CONTENTS. Storage devices.. Optical drives.. Floppy disk.. Hard disk.. Components of Hard disks.. RAID technology.. Reads and writes are equally fast.. Arrays of these disks are used to provide highly reliable storage.. Increasingly popular as they are fast and do not contain moving parts.. Magnetic Disks.. . What is a magnetic disk and how it works. media. PM Video 10:28. Selecting a Hard Drive. Some considerations when selecting a hard drive:. Drive capacity. Today’s hard drives range from 60 GB – 10 TB. Spindle speed (measured in RPM). Common spindle speeds are: 3600, 5400, 7200, 10,000, and 15,000 RPM. In an increasingly competitive market Communication Service Providers CSPs are being forced to quickly adapt to meet customer expectations and market trends by di31erentiating themselves from competit Don Porter. Portions courtesy Emmett . Witchel. 1. Quick Recap. CPU Scheduling. Balance competing concerns with heuristics. What were some goals?. No perfect solution. Today: Block device scheduling.