PPT-Log-Structured File System

LFS 6033 Review Session May 19 2014 Background Problem Sequential HD access is cheap random access is expensive true in 1991 and today Standard UNIX file system does lots of random access for small file writes small reads OK due to caching. Mendel . Rosenblum. and John K. . Ousterhout. Presented . by Travis Bale. 1. Overview. Considerations for File Systems. Problems with Existing File Systems. Log-Structured File System. Sprite LFS Implementation Details. File Concept. Contiguous logical address space. Types: . Data. numeric. character. binary. Program. File Structure. None - sequence of words, bytes. Simple record structure. Lines . Fixed length. Variable length. CS . 355. Operating Systems. Dr. Matthew Wright. Operating System Concepts. chapter 11. File-System Structure. Two design problems:. How should the file system look to the user?. How are logical files mapped onto the physical storage devices?. Where do file systems fit in the OS?. File . control data structures. A common internal interface for file systems. The file system API. File Systems and the OS. . system calls. UNIX FS. DOS FS. CD FS. . in Big Data . and Analytics. Introduction to . Hadoop. Eco-System. Agenda. In this session, you will learn about:. . What is Hadoop. ?. Why Hadoop?. Advantages of Hadoop?. History of . Hadoop. Key Characteristics of . Outline. Overview of file systems. File system design. Sharing files. Unix file system. Consistency and crash recovery. Journaling file systems. Log-structured file . systems. 2. Review. We saw that file systems use write-back caching for improving the performance of file writes. 1. File Concept. Contiguous logical address space. Types: . Data. numeric. character. binary. Program. CS 3100 File-System Interface. 2. File Structure. None - sequence of words, bytes. Simple record structure. Organized Religion: “. a structured system . of faith . or . worship. , especially one followed by a large number of people, such as Christianity, Islam, or Judaism.” . Does the God of the Bible care anything about a structured system of faith or worship? . Perl & Chapter 5. Hey real quick aliases. Aliases. Aliases can be defined on the command line, in . .bash_profile. , or in . .bashrc. , using this form : . alias name=‘command’. unalias. will remove. sees VLeZBo[: ,nteJratLnJ LocaO FLOe S\stems Yupu =KanJ CKrLs DraJJa Andrea ArpacL-Dusseau RemzL ArpacL-D Incredibly popular: Dropbox has 100 million+ usersBack up files to th Outline . File-System Structure. File-System Operations. Directory Implementation. Allocation Methods. Free-Space Management . Efficiency and Performance. Recovery. Example: WAFL File System. Objectives. Interface. File Concept. Access Methods. Directory Structure. Allocation Methods. Objectives. To explain the function of file systems. To describe the interfaces to file systems. To discuss file-system design tradeoffs, including access methods, file sharing, file locking, and directory structures. Contents. File system Structure. File system implementation. Directory implementation. Allocation methods. Contiguous allocation. Linked list allocation. Indexed allocation. Free space management. File System Structure. Lecture # . 12. 1. Today’s Lecture. Function oriented modeling discussion . We’ll discuss the Real-Time Structured Analysis and Structured Design Technique. We’ll apply Real-Time Structured Analysis technique to the Banking System case study today.