PPT-Chapter 8 Adding Disks

Chapter 8 Adding Disks Loops Run instructions again and again and again Check some condition If true repeat 2 types of loops for loop while loop First the variable used in loop condition must be initialized then execution of the loop begins. Alecian Abstract In this chapter I 64257rst present the premain sequence stars around which accretion disks are observed and summarise the main observed characteristics of the classical T Tauri and Herbig AeBe stars I then review the theoretical and 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. I/O Management and Disk Scheduling. Patricia Roy. Manatee Community College, Venice, FL. ©2008, Prentice Hall. Operating Systems:. Internals and Design Principles, 6/E. William Stallings. Given Credit Where It is Due. Phil Armitage. Colorado. Processes in Protoplanetary Disks. Disk structure. Disk evolution. Turbulence. Episodic accretion. Single particle evolution. Ice lines and persistent radial structure. Transient structures in disks. 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. Pawel. . Artymowicz. U of Toronto. MRI turbulence. Some non-MRI turbulence. Roles and the dangers of turbulence. UCSC Santa Cruz 2010. I borrowed some . figures & slides from. X. Wu (2004). R. Nelson (2008). Alhashimi. Storage. Storage . holds data, instructions and information for . future use. .. Storage medium,. also called . secondary storage, . . Is the physical material on which a computer keeps data, instructions and information.. 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. 2. Understanding and Selecting Storage. Save files to a variety of media types, including:. Floppy disks.. Flash random access memory (RAM) devices.. CDs and . DVDs.. Hard disks. . 3. Disk Drives. Hard disk drive. Two main types: Magnetic and Optical. Random access to memory. The hardware must be controlled by driver software called the “controller” in order to be used. Hard Disks, RAID, and Error Handling. Use multiple smaller disks (c.f. one large disk). Parallelism improves performance. Plus extra disk(s) for redundant data storage. Provides fault tolerant storage system. Especially if failed disks can be “hot swapped”. Look how easy it is to add ‘er’ to these words. Have a go at adding ‘er’ to these Did you get them right ? It is just as easy to add ‘est’ to these words. shortshorter CSE 2431: Introduction to Operating Systems. Instructor: Adam C. Champion, Ph.D.. Reading: Chap. 11. , §§13.5, 14.5.6 . [OSC]. Outline. Disk Organization. Disk Performance. Disk Scheduling Algorithms. 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.