DOCSLIB.ORG

OSTA Universal Disk Format Specification Rev. 2.60

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
OSTA Universal Disk Format Specification Rev. 2.60 Universal Disk ® Format Specification Revision 2.60 March 1, 2005 © Copyright 1994-2005 Optical Storage Technology Association ALL RIGHTS RESERVED REVISION HISTORY 1.00 October 24, 1995 Original Release 1.01 November 3, 1995 DVD appendix added 1.02 August 30, 1996 Incorporates Document Change Notices DCN 2-001 through DCN 2-024 1.50 February 4, 1997 Integrated support for CD-R and CD-RW media (DCNs 2-025 thru 2-032) 2.00 April 3, 1998 Integrated support for ECMA 167 3rd Edition which included the support for named streams. (DCN 2-033 through DCN 2-064) 2.01 March 15, 2000 Incorporates DCNs 5000, 5002, 5004, 5006-5009, 5013-5015, 5018-5021, 5024-5027, 5029-5032, 5034-5042, 5044-5048, 5050 2.50 April 30, 2003 Incorporates Metadata Partition, DCNs 5049, 5061-5066, 5068-5072, 5074-5079, 5081-5082, 5086, 5089, 5090. 2.60 January 26, 2005 Incorporates Pseudo OverWrite, DCNs 5100-5121 March 1, 2005 Approved by committee vote. Minor editorial corrections. POINTS OF CONTACT Optical Storage Technology Association UDF Technical Editor http://www.osta.org/ mailto:[email protected] Contact information OSTA UDF Committee email reflector http://www.osta.org/osta/contact.htm See link: “UDF Email Reflector” at the bottom of page: http://www.osta.org/specs/index.htm Technical questions mailto:[email protected] Important Notices __________________________________________________________________________________________________________ (a) THIS DOCUMENT IS AN AUTHORIZED AND APPROVED PUBLICATION OF OSTA. THE SPECIFICATIONS CONTAINED HEREIN ARE THE EXCLUSIVE PROPERTY OF OSTA BUT MAY BE REFERRED TO AND UTILIZED BY THE GENERAL PUBLIC FOR ANY LEGITIMATE PURPOSE, PARTICULARLY IN THE DESIGN AND DEVELOPMENT OF WRITABLE OPTICAL SYSTEMS AND SUBSYSTEMS. THIS DOCUMENT MAY BE COPIED IN WHOLE OR IN PART PROVIDED THAT NO REVISIONS, ALTERATIONS, OR CHANGES OF ANY KIND ARE MADE TO THE MATERIALS CONTAINED HEREIN. (b) COMPLIANCE WITH THIS DOCUMENT MAY REQUIRE USE OF ONE OR MORE FEATURES COVERED BY THE PATENT RIGHTS OF AN OSTA MEMBER, ASSOCIATE OR THIRD PARTY. NO POSITION IS TAKEN BY OSTA WITH RESPECT TO THE VALIDITY OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT, WHETHER OWNED BY A MEMBER OR ASSOCIATE OF OSTA OR OTHERWISE. OSTA HEREBY EXPRESSLY DISCLAIMS ANY LIABILITY FOR INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF OTHERS BY VIRTUE OF THIS OSTA DOCUMENT, NOR DOES OSTA UNDERTAKE A DUTY TO ADVISE USERS OR POTENTIAL USERS OF OSTA DOCUMENTS OF SUCH NOTICES OR ALLEGATIONS. OSTA HEREBY EXPRESSLY ADVISES ALL USERS OR POTENTIAL USERS OF THIS DOCUMENT TO INVESTIGATE AND ANALYZE ANY POTENTIAL INFRINGEMENT SITUATION, SEEK THE ADVICE OF INTELLECTUAL PROPERTY COUNSEL AND, IF INDICATED, OBTAIN A LICENSE UNDER ANY APPLICABLE INTELLECTUAL PROPERTY RIGHT OR TAKE THE NECESSARY STEPS TO AVOID INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT. OSTA EXPRESSLY DISCLAIMS ANY INTENT TO PROMOTE INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT BY VIRTUE OF THE EVOLUTION, ADOPTION, OR PUBLICATION OF THIS OSTA DOCUMENT. (c) ONE OR MORE PATENT HOLDERS HAVE FILED STATEMENTS OF WILLINGNESS TO GRANT A LICENSE, ON REASONABLE AND NONDISCRIMINATORY TERMS, ON A RECIPROCAL BASIS, UNDER PATENT CLAIMS ESSENTIAL TO IMPLEMENT THIS SPECIFICATION. FURTHER INFORMATION MAY BE OBTAINED FROM OSTA. (d) OSTA MAKES NO REPRESENTATION OR WARRANTY REGARDING ANY SPECIFICATION, AND ANY COMPANY USING A SPECIFICATION SHALL DO SO AT ITS SOLE RISK, INCLUDING SPECIFICALLY THE RISKS THAT A PRODUCT DEVELOPED WILL NOT BE COMPATIBLE WITH ANY OTHER PRODUCT OR THAT ANY PARTICULAR PERFORMANCE WILL NOT BE ACHIEVED. OSTA SHALL NOT BE LIABLE FOR ANY EXEMPLARY, INCIDENTAL, PROXIMATE OR CONSEQUENTIAL DAMAGES OR EXPENSES ARISING FROM THE USE OR IMPLEMENTATION OF THIS DOCUMENT. THIS DOCUMENT DEFINES ONLY ONE APPROACH TO COMPATIBILITY, AND OTHER APPROACHES MAY BE AVAILABLE IN THE INDUSTRY. Universal Disk Format® and UDF® are registered marks of the Optical Storage Technology Association. i CONTENTS 1. INTRODUCTION......................................................................................................1 1.1 Document Layout .......................................................................................................................2 1.2 Compliance .................................................................................................................................3 1.3 General References.....................................................................................................................4 1.3.1 References ...............................................................................................................................4 1.3.2 Definitions ...............................................................................................................................4 1.3.3 Terms.......................................................................................................................................7 1.3.4 Acronyms ................................................................................................................................7 2. BASIC RESTRICTIONS & REQUIREMENTS....................................................8 2.1 Part 1 - General ........................................................................................................................11 2.1.1 Character Sets........................................................................................................................11 2.1.2 OSTA CS0 Charspec.............................................................................................................12 2.1.3 Dstrings .................................................................................................................................12 2.1.4 Timestamp .............................................................................................................................13 2.1.5 Entity Identifier .....................................................................................................................14 2.1.6 Descriptor Tag Serial Number at Formatting Time...............................................................19 2.1.7 Volume Recognition Sequence .............................................................................................19 2.2 Part 3 - Volume Structure .......................................................................................................20 2.2.1 Descriptor Tag.......................................................................................................................20 2.2.2 Primary Volume Descriptor...................................................................................................21 2.2.3 Anchor Volume Descriptor Pointer.......................................................................................23 2.2.4 Logical Volume Descriptor ...................................................................................................24 2.2.5 Unallocated Space Descriptor ...............................................................................................26 2.2.6 Logical Volume Integrity Descriptor.....................................................................................26 2.2.7 Implementation Use Volume Descriptor ...............................................................................29 2.2.8 Virtual Partition Map.............................................................................................................31 2.2.9 Sparable Partition Map ..........................................................................................................31 2.2.10 Metadata Partition Map ....................................................................................................32 2.2.11 Virtual Allocation Table ...................................................................................................34 2.2.12 Sparing Table....................................................................................................................36 2.2.13 Metadata Partition.............................................................................................................38 2.2.14 Partition Descriptor...........................................................................................................45 2.3 Part 4 - File Structure ..............................................................................................................47 2.3.1 Descriptor Tag.......................................................................................................................47 2.3.2 File Set Descriptor.................................................................................................................48 2.3.3 Partition Header Descriptor...................................................................................................50 2.3.4 File Identifier Descriptor .......................................................................................................51 2.3.5 ICB Tag .................................................................................................................................54 2.3.6 File Entry...............................................................................................................................56 2.3.7 Unallocated Space Entry .......................................................................................................58 2.3.8 Space Bitmap Descriptor .......................................................................................................59 2.3.9
Load more

Recommended publications
  • Allgemeines Abkürzungsverzeichnis
    Allgemeines Abkürzungsverzeichnis L.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 8,965,180 B2 Knight Et Al
    USOO89651 80B2 (12) United States Patent (10) Patent No.: US 8,965,180 B2 Knight et al. (45) Date of Patent: *Feb. 24, 2015 (54) SYSTEMS AND METHODS FOR 21/4884 (2013.01); H04N 2 1/84 (2013.01); CONVERTING INTERACTIVE MULTIMEDIA H04L 65/602 (2013.01); G1 I B2220/2562 CONTENT AUTHORED FOR DISTRIBUTION (2013.01) VIAA PHYSICAL MEDIUM FOR USPC .......................................................... 386/282 ELECTRONIC DISTRIBUTION (58) Field of Classification Search USPC ......... 386/278, 279, 280, 281, 282,283, 284, (75) Inventors: Anthony David Knight, San Jose, CA 386/285, 290 (US); Ian Michael Lewis, Oxfordshire See application file for complete search history. (GB); Andrew Maurice Devitt, London (GB) (56) References Cited (73) Assignee: Rovi Guides, Inc., Santa Clara, CA (US) U.S. PATENT DOCUMENTS 4,838,843. A 6, 1989 Westhoff (*) Notice: Subject to any disclaimer, the term of this 5,313,881 A 5/1994 Morgan patent is extended or adjusted under 35 U.S.C. 154(b) by 66 days. (Continued) This patent is Subject to a terminal dis FOREIGN PATENT DOCUMENTS claimer. EP O865.362 B1 T 2003 (21) Appl. No.: 13/182,376 JP 2001344828 12/2001 (Continued) (22) Filed: Jul. 13, 2011 OTHER PUBLICATIONS (65) Prior Publication Data Apple Inc., "iTunes Extra iTunes LP Development: Template How US 2012/OO 14674 A1 Jan. 19, 2012 To v1.1”. Jan. 26, 2010, 58 pgs. (Continued) Related U.S. Application Data Primary Examiner — Tat Chio (60) Provisional application No. 61/364,001, filed on Jul. (74) Attorney, Agent, or Firm — Ropes & Gray LLP 13, 2010. (57) ABSTRACT (51) Int.
    [Show full text]
  • Comptia A+ Acronym List Core 1 (220-1001) and Core 2 (220-1002)
    CompTIA A+ Acronym List Core 1 (220-1001) and Core 2 (220-1002) AC: Alternating Current ACL: Access Control List ACPI: Advanced Configuration Power Interface ADF: Automatic Document Feeder ADSL: Asymmetrical Digital Subscriber Line AES: Advanced Encryption Standard AHCI: Advanced Host Controller Interface AP: Access Point APIPA: Automatic Private Internet Protocol Addressing APM: Advanced Power Management ARP: Address Resolution Protocol ASR: Automated System Recovery ATA: Advanced Technology Attachment ATAPI: Advanced Technology Attachment Packet Interface ATM: Asynchronous Transfer Mode ATX: Advanced Technology Extended AUP: Acceptable Use Policy A/V: Audio Video BD-R: Blu-ray Disc Recordable BIOS: Basic Input/Output System BD-RE: Blu-ray Disc Rewritable BNC: Bayonet-Neill-Concelman BSOD: Blue Screen of Death 1 BYOD: Bring Your Own Device CAD: Computer-Aided Design CAPTCHA: Completely Automated Public Turing test to tell Computers and Humans Apart CD: Compact Disc CD-ROM: Compact Disc-Read-Only Memory CD-RW: Compact Disc-Rewritable CDFS: Compact Disc File System CERT: Computer Emergency Response Team CFS: Central File System, Common File System, or Command File System CGA: Computer Graphics and Applications CIDR: Classless Inter-Domain Routing CIFS: Common Internet File System CMOS: Complementary Metal-Oxide Semiconductor CNR: Communications and Networking Riser COMx: Communication port (x = port number) CPU: Central Processing Unit CRT: Cathode-Ray Tube DaaS: Data as a Service DAC: Discretionary Access Control DB-25: Serial Communications
    [Show full text]
  • Silicon Graphics, Inc. Scalable Filesystems XFS & CXFS
    Silicon Graphics, Inc. Scalable Filesystems XFS & CXFS Presented by: Yingping Lu January 31, 2007 Outline • XFS Overview •XFS Architecture • XFS Fundamental Data Structure – Extent list –B+Tree – Inode • XFS Filesystem On-Disk Layout • XFS Directory Structure • CXFS: shared file system ||January 31, 2007 Page 2 XFS: A World-Class File System –Scalable • Full 64 bit support • Dynamic allocation of metadata space • Scalable structures and algorithms –Fast • Fast metadata speeds • High bandwidths • High transaction rates –Reliable • Field proven • Log/Journal ||January 31, 2007 Page 3 Scalable –Full 64 bit support • Large Filesystem – 18,446,744,073,709,551,615 = 264-1 = 18 million TB (exabytes) • Large Files – 9,223,372,036,854,775,807 = 263-1 = 9 million TB (exabytes) – Dynamic allocation of metadata space • Inode size configurable, inode space allocated dynamically • Unlimited number of files (constrained by storage space) – Scalable structures and algorithms (B-Trees) • Performance is not an issue with large numbers of files and directories ||January 31, 2007 Page 4 Fast –Fast metadata speeds • B-Trees everywhere (Nearly all lists of metadata information) – Directory contents – Metadata free lists – Extent lists within file – High bandwidths (Storage: RM6700) • 7.32 GB/s on one filesystem (32p Origin2000, 897 FC disks) • >4 GB/s in one file (same Origin, 704 FC disks) • Large extents (4 KB to 4 GB) • Request parallelism (multiple AGs) • Delayed allocation, Read ahead/Write behind – High transaction rates: 92,423 IOPS (Storage: TP9700)
    [Show full text]
  • W4118: File Systems
    W4118: file systems Instructor: Junfeng Yang References: Modern Operating Systems (3rd edition), Operating Systems Concepts (8th edition), previous W4118, and OS at MIT, Stanford, and UWisc Outline File system concepts . What is a file? . What operations can be performed on files? . What is a directory and how is it organized? File implementation . How to allocate disk space to files? 1 What is a file User view . Named byte array • Types defined by user . Persistent across reboots and power failures OS view . Map bytes as collection of blocks on physical storage . Stored on nonvolatile storage device • Magnetic Disks 2 Role of file system Naming . How to “name” files . Translate “name” + offset logical block # Reliability . Must not lose file data Protection . Must mediate file access from different users Disk management . Fair, efficient use of disk space . Fast access to files 3 File metadata Name – only information kept in human-readable form Identifier – unique tag (number) identifies file within file system (inode number in UNIX) Location – pointer to file location on device Size – current file size Protection – controls who can do reading, writing, executing Time, date, and user identification – data for protection, security, and usage monitoring How is metadata stored? (inode in UNIX) 4 File operations int creat(const char* pathname, mode_t mode) int unlink(const char* pathname) int rename(const char* oldpath, const char* newpath) int open(const char* pathname, int flags, mode_t mode) int read(int fd, void* buf, size_t count); int write(int fd, const void* buf, size_t count) int lseek(int fd, offset_t offset, int whence) int truncate(const char* pathname, offset_t len) ..
    [Show full text]
  • Lecture 17: Files and Directories
    11/1/16 CS 422/522 Design & Implementation of Operating Systems Lecture 17: Files and Directories Zhong Shao Dept. of Computer Science Yale University Acknowledgement: some slides are taken from previous versions of the CS422/522 lectures taught by Prof. Bryan Ford and Dr. David Wolinsky, and also from the official set of slides accompanying the OSPP textbook by Anderson and Dahlin. The big picture ◆ Lectures before the fall break: – Management of CPU & concurrency – Management of main memory & virtual memory ◆ Current topics --- “Management of I/O devices” – Last week: I/O devices & device drivers – Last week: storage devices – This week: file systems * File system structure * Naming and directories * Efficiency and performance * Reliability and protection 1 11/1/16 This lecture ◆ Implementing file system abstraction Physical Reality File System Abstraction block oriented byte oriented physical sector #’s named files no protection users protected from each other data might be corrupted robust to machine failures if machine crashes File system components ◆ Disk management User – Arrange collection of disk blocks into files File File ◆ Naming Naming access – User gives file name, not track or sector number, to locate data Disk management ◆ Security / protection – Keep information secure Disk drivers ◆ Reliability/durability – When system crashes, lose stuff in memory, but want files to be durable 2 11/1/16 User vs. system view of a file ◆ User’s view – Durable data structures ◆ System’s view (system call interface) – Collection of bytes (Unix) ◆ System’s view (inside OS): – Collection of blocks – A block is a logical transfer unit, while a sector is the physical transfer unit.
    [Show full text]
  • CXFSTM Administration Guide for SGI® Infinitestorage
    CXFSTM Administration Guide for SGI® InfiniteStorage 007–4016–025 CONTRIBUTORS Written by Lori Johnson Illustrated by Chrystie Danzer Engineering contributions to the book by Vladmir Apostolov, Rich Altmaier, Neil Bannister, François Barbou des Places, Ken Beck, Felix Blyakher, Laurie Costello, Mark Cruciani, Rupak Das, Alex Elder, Dave Ellis, Brian Gaffey, Philippe Gregoire, Gary Hagensen, Ryan Hankins, George Hyman, Dean Jansa, Erik Jacobson, John Keller, Dennis Kender, Bob Kierski, Chris Kirby, Ted Kline, Dan Knappe, Kent Koeninger, Linda Lait, Bob LaPreze, Jinglei Li, Yingping Lu, Steve Lord, Aaron Mantel, Troy McCorkell, LaNet Merrill, Terry Merth, Jim Nead, Nate Pearlstein, Bryce Petty, Dave Pulido, Alain Renaud, John Relph, Elaine Robinson, Dean Roehrich, Eric Sandeen, Yui Sakazume, Wesley Smith, Kerm Steffenhagen, Paddy Sreenivasan, Roger Strassburg, Andy Tran, Rebecca Underwood, Connie Woodward, Michelle Webster, Geoffrey Wehrman, Sammy Wilborn COPYRIGHT © 1999–2007 SGI. All rights reserved; provided portions may be copyright in third parties, as indicated elsewhere herein. No permission is granted to copy, distribute, or create derivative works from the contents of this electronic documentation in any manner, in whole or in part, without the prior written permission of SGI. LIMITED RIGHTS LEGEND The software described in this document is "commercial computer software" provided with restricted rights (except as to included open/free source) as specified in the FAR 52.227-19 and/or the DFAR 227.7202, or successive sections. Use beyond
    [Show full text]
  • Operating Systems Lecture #5: File Management
    Operating Systems Lecture #5: File Management Written by David Goodwin based on the lecture series of Dr. Dayou Li and the book Understanding Operating Systems 4thed. by I.M.Flynn and A.McIver McHoes (2006) Department of Computer Science and Technology, University of Bedfordshire. Operating Systems, 2013 25th February 2013 Outline Lecture #5 File Management David Goodwin 1 Introduction University of Bedfordshire 2 Interaction with the file manager Introduction Interaction with the file manager 3 Files Files Physical storage 4 Physical storage allocation allocation Directories 5 Directories File system Access 6 File system Data compression summary 7 Access 8 Data compression 9 summary Operating Systems 46 Lecture #5 File Management David Goodwin University of Bedfordshire Introduction 3 Interaction with the file manager Introduction Files Physical storage allocation Directories File system Access Data compression summary Operating Systems 46 Introduction Lecture #5 File Management David Goodwin University of Bedfordshire Introduction 4 Responsibilities of the file manager Interaction with the file manager 1 Keep track of where each file is stored Files 2 Use a policy that will determine where and how the files will Physical storage be stored, making sure to efficiently use the available storage allocation space and provide efficient access to the files. Directories 3 Allocate each file when a user has been cleared for access to File system it, and then record its use. Access 4 Deallocate the file when the file is to be returned to storage, Data compression and communicate its availability to others who may be summary waiting for it. Operating Systems 46 Definitions Lecture #5 File Management field is a group of related bytes that can be identified by David Goodwin University of the user with a name, type, and size.
    [Show full text]
  • Data Interchange on Parallel Write/Read Disk Format for 5 Optical Disks
    ECMA-405 1st Edition / December 2013 Data Interchange on Parallel Write/Read Disk Format for 5 Optical Disks Reference number ECMA-123:2009 © Ecma International 2009 COPYRIGHT PROTECTED DOCUMENT © Ecma International 2013 Contents Page 1 Scope ...................................................................................................................................................... 1 2 Conformance ......................................................................................................................................... 1 3 Normative references ............................................................................................................................ 1 4 Terms and definitions ........................................................................................................................... 1 5 Conventions and notations .................................................................................................................. 4 6 Recording area for non-parity disk type ............................................................................................. 4 6.1 General ................................................................................................................................................... 4 6.2 System management area .................................................................................................................... 4 6.2.1 General ..................................................................................................................................................
    [Show full text]
  • Introduction to ISO 9660
    Disc Manufacturing, Inc. A QUIXOTE COMPANY Introduction to ISO 9660, what it is, how it is implemented, and how it has been extended. Clayton Summers Copyright © 1993 by Disc Manufacturing, Inc. All rights reserved. WHO IS DMI? Disc Manufacturing, Inc. (DMI) manufactures all compact disc formats (i.e., CD-Audio, CD-ROM, CD-ROM XA, CDI, PHOTO CD, 3DO, KARAOKE, etc.) at two plant sites in the U.S.; Huntsville, AL, and Anaheim, CA. To help you, DMI has one of the largest Product Engineering/Technical Support staff and sales force dedicated solely to CD-ROM in the industry. The company has had a long term commitment to optical disc technology and has performed developmental work and manufactured (laser) optical discs of various types since 1981. In 1983, DMI manufactured the first compact disc in the United States. DMI has developed extensive mastering expertise during this time and is frequently called upon by other companies to provide special mastering services for products in development. In August 1991, DMI purchased the U.S. CD-ROM business from the Philips and Du Pont Optical Company (PDO). PDO employees in sales, marketing and technical services were retained. DMI is a wholly-owned subsidiary of Quixote Corporation, a publicly owned corporation whose stock is traded on the NASDAQ exchange as QUIX. Quixote is a diversified technology company composed of Energy Absorption Systems, Inc. (manufactures highway crash cushions), Stenograph Corporation (manufactures shorthand machines and computer systems for court reporting) and Disc Manufacturing, Inc. We would be pleased to help you with your CD project or answer any questions you may have.
    [Show full text]
  • Standardizing Information and Communication Systems
    ECMA/TC39/97/7 ECMA/GA/97/8 Standardizing Information and Communication Systems Minutes of the 2nd meeting of TC39 held in Cupertino, USA, on 14th - 15th January 1997 Chairman: Mr. G. Robinson (Sun) Secretary: Mr. J. van den Beld (SG ECMA) Attending: Ms. Brennan (Apple), Mr. Coha (HP), Ms. Converse (Netscape), Mr. Espinosa (Apple), Mr. Gibbons (HP), Mr. Katzenberger (Microsoft), Mr. Ksar (HP), Mr. Lenkov (HP), Mr. Matzke (Apple), Ms. Nguyen (Netscape), Mr. Saraiya (Sun), Mr. Smith (Digital), Mr. Urquhart (Sun), Mr. Willingmyre (Microsoft), Mr. Wiltamuth (Microsoft) Guests: Mr. Gardner (Borland), Mr. Palay (Silicon Graphics), Mr. Seniak (Ilog), Mr. Solton (Borland), Mr. Turyn (Nombas) Excused: Mr. Cargill, Mr. Fisher, Mr. Mathis, Mr. Reardon, Mr. Singer 1 Opening and adoption of the agenda (96/7) Mr. Robinson, Chairman of TC39, opened the meeting and welcomed all attendants, in particular those attending for the first time. A roll call was held. The agenda was approved, with some detailing proposed by the Chairman. 2 Approval of the minutes of the 1st meeting (96/4) The minutes were approved without modifications. 3 Matters arising from the minutes not covered elsewhere None. 4 Documents 97/2: A list of names proposed to replace ECMAScript, prepared by Mr. Wiltamuth, and also distributed via the TC39 reflector on 13th January 1997. 97/3: A proposal of lists of objects to be included into clauses 11 to 13 of the draft standard, prepared by Mr. Wiltamuth (paper document only). 97/4: Comments on the draft standard, version 0.2, prepared byMr. Noorda (paper document only). 5 Reports 5.1 ECMA General Assembly No.
    [Show full text]
  • File System Layout
    File Systems Main Points • File layout • Directory layout • Reliability/durability Named Data in a File System index !le name directory !le number structure storage o"set o"set block Last Time: File System Design Constraints • For small files: – Small blocks for storage efficiency – Files used together should be stored together • For large files: – ConCguous allocaon for sequenCal access – Efficient lookup for random access • May not know at file creaon – Whether file will become small or large File System Design Opons FAT FFS NTFS Index Linked list Tree Tree structure (fixed, asym) (dynamic) granularity block block extent free space FAT array Bitmap Bitmap allocaon (fixed (file) locaon) Locality defragmentaon Block groups Extents + reserve Best fit space defrag MicrosoS File Allocaon Table (FAT) • Linked list index structure – Simple, easy to implement – SCll widely used (e.g., thumb drives) • File table: – Linear map of all blocks on disk – Each file a linked list of blocks FAT MFT Data Blocks 0 1 2 3 !le 9 block 3 4 5 6 7 8 9 !le 9 block 0 10 !le 9 block 1 11 !le 9 block 2 12 !le 12 block 0 13 14 15 16 !le 12 block 1 17 18 !le 9 block 4 19 20 FAT • Pros: – Easy to find free block – Easy to append to a file – Easy to delete a file • Cons: – Small file access is slow – Random access is very slow – Fragmentaon • File blocks for a given file may be scaered • Files in the same directory may be scaered • Problem becomes worse as disk fills Berkeley UNIX FFS (Fast File System) • inode table – Analogous to FAT table • inode – Metadata • File owner, access permissions,
    [Show full text]