DOCSLIB.ORG

Introduction to High Performance Computing at Case Western Reserve University ! HPC Access & Linux [email protected]

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Introduction to High Performance Computing at Case Western Reserve University ! HPC Access & Linux [email protected] KSL Data Center Working on the Cluster • The command line: How does it work? • Connecting to the cluster • Files & directories • Navigating • Creating, Editing, Moving/Renaming • The file structure: What & How? • The session environment • Variables • Modules & Hierarchies Why do we learn to use the shell? • Repeating a workflow can be labour intensive • Allows to automate repetitive tasks • Capture small data manipulation steps to make research reproducible • Manual manipulation of data files: • is often not captured in documentation • is hard to reproduce; troubleshoot; review; or improve • The Shell allows… • Workflows can be automated through the use of shell scripts • Focus on easy string manipulation (e.g. sort, grep, etc.) • Every step can be captured, enhancing reproducibility and troubleshooting What does the “Shell” Do? • The shell is a process providing the CLI • The heart of a cli is a read-evaluate-print loop, or REPL: you type a command, press Enter, the shell: • Reads it • Executes (or “evaluates” it) • Prints the output • Then restores the prompt, waits for you to enter another command Linux Shell Concepts • path/absolute path: specify the location of a file/dir • current working directory: applies in a shell session • filename extension: a label, indicates data type • home directory: ‘privileged’ location, easy to reference • Shell script: interpreted program to automate tasks • Standard Input: The input channel to a process • Standard Output & Error: output channels • Redirection - - change the standard ‘flow’ (source) Access the Cluster You can login from anywhere You will need: • An approved cluster account • Enter your CaseID and the Single Sign-On password • ssh (secure shell) utility [detailed instructions for all platforms] • web browser (https) via OnDemand web portal If Off-campus Location, then Connect through VPN, using two-factor authentication Case Guest wireless == “off-campus” Accessing the Cluster • using ssh command: Form and options • ssh [options] <user>@<hostname> • e.g. ssh -X [email protected] - - results in, • a network connection through ‘rider.case.edu’ to a headnode • from the ‘-X’ option, a graphical channel is created • Usage: • need to run for each window • creates an independent process • Access the Cluster Access the Cluster Owner Group Permissions Ownership & Permissions Ownership categories: user, group, other, all •When creating files, they will be ‘owned’ by your account •Only one group membership is active at any time ! Permissions: read, write, execute •execute: directories, allows ‘traversal’; files indicates executable Files & Directories Navigating • How to see or find files and directories ➡ listing, finding and searching (within) files • How to move within the file system ➡ changing directories or computers • How to specify locations within the cluster ➡ paths: current, absolute, relative Files & Directories How to see or find files and directories • The list command — ls • ls [OPTION]... [FILE]… • let’s ask for help in an example, using ‘- - help’ [demo] • options • - l : long-list, provides details (shows directory contents) • - d : only list a directory, don’t show contents • - Sh : size + ‘human’-readable output (typically for storage utilization) • - t : time-order • - r : reverse the ordering Files & Directories How to specify locations • what’s in a correct path name? • adequate information for the shell to recognize the destination • the references must respect the filesystem (we’ll review later) • current working directory is the reference point • moving downward just requires a subdirectory name • moving outside requires full pathname or a proper relative path • Check current path • ‘pwd’ — path to current working directory Files & Directories How to move within the file system • The ‘change directory’ command — cd • cd <destination path> • <destination path> — may use full or relative path names • usage • ‘ch /home/<caseid>’ — change to /home/<caseid> • ’cd $HOME’ — $HOME is an environment variable • ‘cd’ — no argument == go to home dir • ‘cd /scratch/pbsjobs/job.8364141.hpc’ — full pathname • ‘ch ..’ — move up one directory; special instance relative path Files & Directories Creating, Editing, Moving/Renaming • creating • mkdir — Directories • touch — File (empty) • vi, nano, emacs — File, and provide an editor • Moving/Renaming • cp [-r] <source-path> <destination-path> • mv <source-path> <destination-path> • rm -r <target-path> use with caution — the shell does not forgive Accessing the Cluster • Web Portal service: https://ondemand.case.edu • No installation, access via browser using SSO • https rather than ssh -- no X11 graphics software required • shell; file manager; job status & submission • desktop environment; jupyter, rstudio interactive web applications • More interactive applications to follow • From within CWRU Campus Network Accessing the Cluster • Graphical Environment Options via X11 • ssh -X <user>@<hostname> • e.g. ssh -X [email protected] - - results in, • a network connection through ‘rider.case.edu’ to a headnode • from the ‘-X’ option, a graphical channel is created • x2go-client: Improved efficiency & capabilities • Full desktop environment • Install & config instructions: CWRU HPCC documentation Rider Cluster Components ! University rider.case.edu ondemand.case.edu Firewall ! Admin SLURM Science Head Nodes Nodes Master DMZ Resource Manager Data Transfer Disk Storage Nodes Batch nodes GPU nodes SMP nodes Markov Cluster Components ! University markov.case.edu ondemand.case.edu Firewall ! Admin SLURM Science Head Nodes Nodes Master DMZ Resource Manager Data Transfer Disk Storage Nodes class (GPU) nodes Working within Group Allocations - I • Review: What are linux groups? • Manage affiliations in the multiuser environment • Set “in-between” permissions: u <— g —> o • Groups are administered — contact [email protected] • Switching the active group: “newgrp - <groupname>” [mrd20@hpc3 ~] groups tas35 oscsys gaussian hpcadmin schrodinger ccm4 singularity [mrd20@hpc3 ~] newgrp - hpcadmin [mrd20@hpc3 ~] groups hpcadmin oscsys gaussian tas35 schrodinger ccm4 singularity Working within Group Allocations - II • Creating a file/directory with the intended ownership • newgrp hpcadmin • mkdir <new directory> • Changing ownership after creating a file/directory • mkdir new-directory • ls -l new-directory HPC Environment Group Cluster Resources Your HPC account, sponsored by your PI, provides: ! •Group affiliation — resources shared amongst group members •Storage •/home — permanent storage, replicated & “snapshot” protected •/scratch/pbsjobs — up to 1 TB temporary storage •/scratch/users — small-scale temporary storage ➡ exceeding quota(s) will prevent using account!! ! •Cores: member groups allocation of, typically, 64 per unit • Wall-time: 320-hour limit for member shares (36 hours for guest units) HPC Environment Your /home •Allocated storage space in the HPC filesystem for your work •Create subdirectories underneath your /home/CaseID, ideally each job has its own subdirectory ! cd — linux command to change the current directory examples to change to “home” ‣cd /home/<CaseID> ‣cd ~<CaseID> ‣cd $HOME ! $HOME is an environment variable that points to /home/<CaseID> HPC Environment File Structure / [root] /home /scratch /mnt /usr /usr/bin /home/<caseid> /scratch/pbsjobs /mnt/pan /usr/lib xxx accounts for scheduled jobs additional high-! system ! performance storage executables ! and libraries /scratch/users /mnt/projects general purpose ! research storage /usr/local temp storage installed software HPC Environment: Environment Variables on Rider Keeping organized ! ‣echo $PATH /usr/local/intel-17/openmpi/2.0.1/bin:/usr/local/intel/17/compilers_and_libraries_2017/linux/bin/intel64:/ usr/lib64/qt-3.3/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/opt/dell/srvadmin/bin! ! ‣echo $LD_LIBRARY_PATH /usr/local/intel-17/openmpi/2.0.1/lib:/usr/local/intel/17/tbb/lib/intel64/gcc4.7:/usr/local/intel/17/ compilers_and_libraries_2017/linux/mkl/lib/intel64:/usr/local/intel/17/compilers_and_libraries_2017/ linux/lib/intel64::/usr/local/lib Changes: slurm commands in /usr/bin —> no longer referenced in the PATH, etc Modules and Environment Module command: avail, spider, list, load, unload Manage the environment necessary to run your applications (binary, libraries, shortcuts) Modify environment variables using module commands: >>module avail & spider — learn what is available and how to load it >>module list (shows modules loaded in your environment) >>module load python (loads default version) >>module load python/3.5.1 (loads specific version) >>module unload python/3.5.1 (unloads specific version) >>module purge — {when all else fails, and you don’t want to start a new shell session….} ! ------------------------------------------------------------------- Modules and Environment On Rider, you might need to load a particular version of a compiler and OpenMPI in order to find your module. Command Outcome Shows the list of the current loadable modules of a module avail hierarchy. It also shows, visually, which modules are loaded. module spider Shows the list of all modules and versions available. module spider/<ver> Shows how to load the specific module version Modules and Environment Lua module hierarchies — independence & accountability • Core — persistent, independent: no run-time dependence on other packages • Compilers
Recommended publications
  • The Microsoft Compound Document File Format"

    The Microsoft Compound Document File Format"

    OpenOffice.org's Documentation of the Microsoft Compound Document File Format Author Daniel Rentz ✉ mailto:[email protected] http://sc.openoffice.org License Public Documentation License Contributors Other sources Hyperlinks to Wikipedia ( http://www.wikipedia.org) for various extended information Mailing list ✉ mailto:[email protected] Subscription ✉ mailto:[email protected] Download PDF http://sc.openoffice.org/compdocfileformat.pdf XML http://sc.openoffice.org/compdocfileformat.odt Project started 2004-Aug-30 Last change 2007-Aug-07 Revision 1.5 Contents 1 Introduction ......................................................................................................... 3 1.1 License Notices 3 1.2 Abstract 3 1.3 Used Terms, Symbols, and Formatting 4 2 Storages and Streams ........................................................................................... 5 3 Sectors and Sector Chains ................................................................................... 6 3.1 Sectors and Sector Identifiers 6 3.2 Sector Chains and SecID Chains 7 4 Compound Document Header ............................................................................. 8 4.1 Compound Document Header Contents 8 4.2 Byte Order 9 4.3 Sector File Offsets 9 5 Sector Allocation ............................................................................................... 10 5.1 Master Sector Allocation Table 10 5.2 Sector Allocation Table 11 6 Short-Streams ...................................................................................................
  • Mac OS X Server Administrator's Guide

    Mac OS X Server Administrator's Guide

    034-9285.S4AdminPDF 6/27/02 2:07 PM Page 1 Mac OS X Server Administrator’s Guide K Apple Computer, Inc. © 2002 Apple Computer, Inc. All rights reserved. Under the copyright laws, this publication may not be copied, in whole or in part, without the written consent of Apple. The Apple logo is a trademark of Apple Computer, Inc., registered in the U.S. and other countries. Use of the “keyboard” Apple logo (Option-Shift-K) for commercial purposes without the prior written consent of Apple may constitute trademark infringement and unfair competition in violation of federal and state laws. Apple, the Apple logo, AppleScript, AppleShare, AppleTalk, ColorSync, FireWire, Keychain, Mac, Macintosh, Power Macintosh, QuickTime, Sherlock, and WebObjects are trademarks of Apple Computer, Inc., registered in the U.S. and other countries. AirPort, Extensions Manager, Finder, iMac, and Power Mac are trademarks of Apple Computer, Inc. Adobe and PostScript are trademarks of Adobe Systems Incorporated. Java and all Java-based trademarks and logos are trademarks or registered trademarks of Sun Microsystems, Inc. in the U.S. and other countries. Netscape Navigator is a trademark of Netscape Communications Corporation. RealAudio is a trademark of Progressive Networks, Inc. © 1995–2001 The Apache Group. All rights reserved. UNIX is a registered trademark in the United States and other countries, licensed exclusively through X/Open Company, Ltd. 062-9285/7-26-02 LL9285.Book Page 3 Tuesday, June 25, 2002 3:59 PM Contents Preface How to Use This Guide 39 What’s Included
  • Alias Manager 4

    Alias Manager 4

    CHAPTER 4 Alias Manager 4 This chapter describes how your application can use the Alias Manager to establish and resolve alias records, which are data structures that describe file system objects (that is, files, directories, and volumes). You create an alias record to take a “fingerprint” of a file system object, usually a file, that you might need to locate again later. You can store the alias record, instead of a file system specification, and then let the Alias Manager find the file again when it’s needed. The Alias Manager contains algorithms for locating files that have been moved, renamed, copied, or restored from backup. Note The Alias Manager lets you manage alias records. It does not directly manipulate Finder aliases, which the user creates and manages through the Finder. The chapter “Finder Interface” in Inside Macintosh: Macintosh Toolbox Essentials describes Finder aliases and ways to accommodate them in your application. ◆ The Alias Manager is available only in system software version 7.0 or later. Use the Gestalt function, described in the chapter “Gestalt Manager” of Inside Macintosh: Operating System Utilities, to determine whether the Alias Manager is present. Read this chapter if you want your application to create and resolve alias records. You might store an alias record, for example, to identify a customized dictionary from within a word-processing document. When the user runs a spelling checker on the document, your application can ask the Alias Manager to resolve the record to find the correct dictionary. 4 To use this chapter, you should be familiar with the File Manager’s conventions for Alias Manager identifying files, directories, and volumes, as described in the chapter “Introduction to File Management” in this book.
  • Answers to Even- Numbered Exercises 5

    Answers to Even- Numbered Exercises 5

    Answers to Even- Numbered Exercises 5 from page 163 1. What does the shell ordinarily do while a command is executing? What should you do if you do not want to wait for a command to finish before running another command? 2. Using sort as a filter, rewrite the following sequence of commands: $ sort list > temp $ lpr temp $ rm temp $ cat list | sort | lpr 3. What is a PID number? Why are they useful when you run processes in the background? 4. Assume that the following files are in the working directory: $ ls intro notesb ref2 section1 section3 section4b notesa ref1 ref3 section2 section4a sentrev Give commands for each of the following, using wildcards to express filenames with as few characters as possible. 1 2 Chapter 5 Answers to Exercises a. List all files that begin with section. $ ls section* b. List the section1, section2, and section3 files only. $ ls section[1-3] c. List the intro file only. $ ls i* d. List the section1, section3, ref1, and ref3 files. $ ls *[13] 5. Refer to the documentation of utilities in Part III or the man pages to determine what commands will a. Output the number of lines in the standard input that contain the word a or A. b. Output only the names of the files in the working directory that contain the pattern $(. c. List the files in the working directory in their reverse alphabetical order. d. Send a list of files in the working directory to the printer, sorted by size. 6. Give a command to a. Redirect the standard output from a sort command into a file named phone_list.
  • Efficient Metadata Management in Cloud Computing

    Efficient Metadata Management in Cloud Computing

    Send Orders for Reprints to [email protected] The Open Cybernetics & Systemics Journal, 2015, 9, 1485-1489 1485 Open Access Efficient Metadata Management in Cloud Computing Yu Shuchun1,* and Huang Bin2 1Deptment of Computer Engineering, Huaihua University, Huaihua, Hunan, 418008, P.R. China; 2School of Mathmatic and Computer Science, Guizhou Normal University, Guiyang, Guizhou, 550001, P.R. China Abstract: Existing metadata management methods bring about lower access efficiency in solving the problem of renam- ing directory. This paper proposes a metadata management method based on directory path redirection (named as DPRD) which includes the data distribution method based on directory path and the directory renaming method based on directory path redirection. Experiments show that DPRD effectively solves the lower access efficiency caused by the renaming di- rectory. Keywords: Cloud computing, directory path, redirection, metadata. 1. INTRODUCTION renaming a directory. The directory path fixed numbering (marked as DPFN) [10, 11] endows the globally unique ID With the prevalence of Internet application and data- (DPID) for each directory path, and DPID remains un- intensive computing, there are many new application sys- changed in the life cycle of the directory path, and the meta- tems in cloud computing environment. These systems are data of all files (or sub-directories) in the directory path will mainly characterized by [1-3]: (1) The enormous files stored be placed and achieved according to its hash value of DPID. in the system, some even reach trillions level, and it still in- It can solve the metadata migration issue caused by directory crease rapidly; (2) The user number and daily access are renaming, but it uses a directory path index server to manage quire enormous, reaching billions level.
  • Your Performance Task Summary Explanation

    Your Performance Task Summary Explanation

    Lab Report: 11.2.5 Manage Files Your Performance Your Score: 0 of 3 (0%) Pass Status: Not Passed Elapsed Time: 6 seconds Required Score: 100% Task Summary Actions you were required to perform: In Compress the D:\Graphics folderHide Details Set the Compressed attribute Apply the changes to all folders and files In Hide the D:\Finances folder In Set Read-only on filesHide Details Set read-only on 2017report.xlsx Set read-only on 2018report.xlsx Do not set read-only for the 2019report.xlsx file Explanation In this lab, your task is to complete the following: Compress the D:\Graphics folder and all of its contents. Hide the D:\Finances folder. Make the following files Read-only: D:\Finances\2017report.xlsx D:\Finances\2018report.xlsx Complete this lab as follows: 1. Compress a folder as follows: a. From the taskbar, open File Explorer. b. Maximize the window for easier viewing. c. In the left pane, expand This PC. d. Select Data (D:). e. Right-click Graphics and select Properties. f. On the General tab, select Advanced. g. Select Compress contents to save disk space. h. Click OK. i. Click OK. j. Make sure Apply changes to this folder, subfolders and files is selected. k. Click OK. 2. Hide a folder as follows: a. Right-click Finances and select Properties. b. Select Hidden. c. Click OK. 3. Set files to Read-only as follows: a. Double-click Finances to view its contents. b. Right-click 2017report.xlsx and select Properties. c. Select Read-only. d. Click OK. e.
  • The Linux Command Line

    The Linux Command Line

    The Linux Command Line Fifth Internet Edition William Shotts A LinuxCommand.org Book Copyright ©2008-2019, William E. Shotts, Jr. This work is licensed under the Creative Commons Attribution-Noncommercial-No De- rivative Works 3.0 United States License. To view a copy of this license, visit the link above or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042. A version of this book is also available in printed form, published by No Starch Press. Copies may be purchased wherever fine books are sold. No Starch Press also offers elec- tronic formats for popular e-readers. They can be reached at: https://www.nostarch.com. Linux® is the registered trademark of Linus Torvalds. All other trademarks belong to their respective owners. This book is part of the LinuxCommand.org project, a site for Linux education and advo- cacy devoted to helping users of legacy operating systems migrate into the future. You may contact the LinuxCommand.org project at http://linuxcommand.org. Release History Version Date Description 19.01A January 28, 2019 Fifth Internet Edition (Corrected TOC) 19.01 January 17, 2019 Fifth Internet Edition. 17.10 October 19, 2017 Fourth Internet Edition. 16.07 July 28, 2016 Third Internet Edition. 13.07 July 6, 2013 Second Internet Edition. 09.12 December 14, 2009 First Internet Edition. Table of Contents Introduction....................................................................................................xvi Why Use the Command Line?......................................................................................xvi
  • Filesystem Hierarchy Standard

    Filesystem Hierarchy Standard

    Filesystem Hierarchy Standard LSB Workgroup, The Linux Foundation Filesystem Hierarchy Standard LSB Workgroup, The Linux Foundation Version 3.0 Publication date March 19, 2015 Copyright © 2015 The Linux Foundation Copyright © 1994-2004 Daniel Quinlan Copyright © 2001-2004 Paul 'Rusty' Russell Copyright © 2003-2004 Christopher Yeoh Abstract This standard consists of a set of requirements and guidelines for file and directory placement under UNIX-like operating systems. The guidelines are intended to support interoperability of applications, system administration tools, development tools, and scripts as well as greater uniformity of documentation for these systems. All trademarks and copyrights are owned by their owners, unless specifically noted otherwise. Use of a term in this document should not be regarded as affecting the validity of any trademark or service mark. Permission is granted to make and distribute verbatim copies of this standard provided the copyright and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this standard under the conditions for verbatim copying, provided also that the title page is labeled as modified including a reference to the original standard, provided that information on retrieving the original standard is included, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this standard into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the copyright holder. Dedication This release is dedicated to the memory of Christopher Yeoh, a long-time friend and colleague, and one of the original editors of the FHS.
  • What Is UNIX? the Directory Structure Basic Commands Find

    What Is UNIX? the Directory Structure Basic Commands Find

    What is UNIX? UNIX is an operating system like Windows on our computers. By operating system, we mean the suite of programs which make the computer work. It is a stable, multi-user, multi-tasking system for servers, desktops and laptops. The Directory Structure All the files are grouped together in the directory structure. The file-system is arranged in a hierarchical structure, like an inverted tree. The top of the hierarchy is traditionally called root (written as a slash / ) Basic commands When you first login, your current working directory is your home directory. In UNIX (.) means the current directory and (..) means the parent of the current directory. find command The find command is used to locate files on a Unix or Linux system. find will search any set of directories you specify for files that match the supplied search criteria. The syntax looks like this: find where-to-look criteria what-to-do All arguments to find are optional, and there are defaults for all parts. where-to-look defaults to . (that is, the current working directory), criteria defaults to none (that is, select all files), and what-to-do (known as the find action) defaults to ‑print (that is, display the names of found files to standard output). Examples: find . –name *.txt (finds all the files ending with txt in current directory and subdirectories) find . -mtime 1 (find all the files modified exact 1 day) find . -mtime -1 (find all the files modified less than 1 day) find . -mtime +1 (find all the files modified more than 1 day) find .
  • Lecture 17: Files and Directories

    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.
  • File Systems

    File Systems

    File Systems Profs. Bracy and Van Renesse based on slides by Prof. Sirer Storing Information • Applications could store information in the process address space • Why is this a bad idea? – Size is limited to size of virtual address space – The data is lost when the application terminates • Even when computer doesn’t crash! – Multiple process might want to access the same data File Systems • 3 criteria for long-term information storage: 1. Able to store very large amount of information 2. Information must survive the processes using it 3. Provide concurrent access to multiple processes • Solution: – Store information on disks in units called files – Files are persistent, only owner can delete it – Files are managed by the OS File Systems: How the OS manages files! File Naming • Motivation: Files abstract information stored on disk – You do not need to remember block, sector, … – We have human readable names • How does it work? – Process creates a file, and gives it a name • Other processes can access the file by that name – Naming conventions are OS dependent • Usually names as long as 255 characters is allowed • Windows names not case sensitive, UNIX family is File Extensions • Name divided into 2 parts: Name+Extension • On UNIX, extensions are not enforced by OS – Some applications might insist upon them • Think: .c, .h, .o, .s, etc. for C compiler • Windows attaches meaning to extensions – Tries to associate applications to file extensions File Access • Sequential access – read all bytes/records from the beginning – particularly convenient for magnetic tape • Random access – bytes/records read in any order – essential for database systems File Attributes • File-specific info maintained by the OS – File size, modification date, creation time, etc.
  • Filesystem Hierarchy Standard

    Filesystem Hierarchy Standard

    Filesystem Hierarchy Standard Filesystem Hierarchy Standard Group Edited by Rusty Russell Daniel Quinlan Filesystem Hierarchy Standard by Filesystem Hierarchy Standard Group Edited by Rusty Russell and Daniel Quinlan Published November 4 2003 Copyright © 1994-2003 Daniel Quinlan Copyright © 2001-2003 Paul ’Rusty’ Russell Copyright © 2003 Christopher Yeoh This standard consists of a set of requirements and guidelines for file and directory placement under UNIX-like operating systems. The guidelines are intended to support interoperability of applications, system administration tools, development tools, and scripts as well as greater uniformity of documentation for these systems. All trademarks and copyrights are owned by their owners, unless specifically noted otherwise. Use of a term in this document should not be regarded as affecting the validity of any trademark or service mark. Permission is granted to make and distribute verbatim copies of this standard provided the copyright and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this standard under the conditions for verbatim copying, provided also that the title page is labeled as modified including a reference to the original standard, provided that information on retrieving the original standard is included, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this standard into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the copyright holder. Table of Contents 1. Introduction........................................................................................................................................................1 1.1.