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A Brief History of UNIX File Systems
A Brief History of UNIX File Systems Val Henson IBM, Inc. [email protected] Summary • Review of UNIX file system concepts • File system formats, 1974-2004 • File system comparisons and recommendations • Fun trivia • Questions and answers (corrections ONLY during talk) 1 VFS/vnode architecture • VFS: Virtual File System: common object-oriented interface to fs's • vnode: virtual node: abstract file object, includes vnode ops • All operations to fs's and files done through VFS/vnode in- terface • S.R. Kleiman, \Vnodes: An Architecture for Multiple File System Types in Sun UNIX," Summer USENIX 1986 2 Some Definitions superblock: fs summary, pointers to other information inode: on-disk structure containing information about a file indirect block: block containing pointers to other blocks metadata: everything that is not user data, including directory entries 3 Disk characteristics • Track - contiguous region, can be read at maximum speed • Seek time - time to move the head between different tracks • Rotational delay - time for part of track to move under head • Fixed per I/O overhead means bigger I/Os are better 4 In the beginning: System V FS (S5FS) (c. 1974) • First UNIX file system, referred to as \FS" • Disk layout: superblock, inodes, followed by everything else • 512-1024 byte block size, no fragments • Super simple - and super slow! 2-5% of raw disk bandwidth 5 Berkeley Fast File System (FFS or UFS) (c. 1984) • Metadata spread throughout the disk in \cylinder groups" • Block size 4KB minimum, frag size 1KB (to avoid 45% wasted space) • Physical -
THE Advancedlinux
THE advanced linux POCKETBOOK This Pocketbook is for Advanced users of Linux. If you find the information over your head, we recommend that Editorial you look at the 2003 Edition Linux Pocketbook, which can be found on last month’s cover CD. If you missed out, Hello and welcome to the 2003 Edition of the Advanced Linux Pocketbook. Last month we gave you the updated Linux Pocketbook, so by now you should be an old then don’t worry... we can help you! Call 136 116 or visit hand when it comes to the basics; installing software, configuring settings, and www.magshop.com.au to order your back issue for connecting to other machines. You should be at least savvy when it comes to the command line, even if you can’t do much more than manipulate files. Grep should $9.80 + $6.50 for postage within Australia. be in your bag of tricks, and your fingers should gravitate to the ‘l’ and ‘s’ keys automatically when you sit idle at the console. If you’re keen to learn how to make the most out of Linux, you’re in the right place. While the first book dealt with how May the source be with you! to get Linux up and running on your system, this Advanced Pocketbook develops your skills from there. Remember back to when you installed your first Linux distribution and looked up to the geeks that seemed to know so much more about this obscure yet powerful operating system. They dazzled you with talk of Python scripts, pages built using PHPNuke, and staying up late at night, fuelled by litres of Jolt cola, to recompile their kernels. -
Set Hadoop-Specific Environment Variables Here
# Set Hadoop-specific environment variables here. # The only required environment variable is JAVA_HOME. All others are # optional. When running a distributed configuration it is best to # set JAVA_HOME in this file, so that it is correctly defined on # remote nodes. # The java implementation to use. Required. export JAVA_HOME=/usr/jdk64/jdk1.8.0_112 export HADOOP_HOME_WARN_SUPPRESS=1 # Hadoop home directory export HADOOP_HOME=${HADOOP_HOME:-/usr/hdp/2.6.5.0-292/hadoop} # Hadoop Configuration Directory # Path to jsvc required by secure HDP 2.0 datanode export JSVC_HOME=/usr/lib/bigtop-utils # The maximum amount of heap to use, in MB. Default is 1000. export HADOOP_HEAPSIZE="1024" export HADOOP_NAMENODE_INIT_HEAPSIZE="-Xms1024m" # Extra Java runtime options. Empty by default. export HADOOP_OPTS="-Djava.net.preferIPv4Stack=true ${HADOOP_OPTS}" USER="$(whoami)" # Command specific options appended to HADOOP_OPTS when specified HADOOP_JOBTRACKER_OPTS="-server -XX:ParallelGCThreads=8 -XX:+UseConcMarkSweepGC - XX:ErrorFile=/var/log/hadoop/$USER/hs_err_pid%p.log -XX:NewSize=200m -XX:MaxNewSize=200m - Xloggc:/var/log/hadoop/$USER/gc.log-`date +'%Y%m%d%H%M'` -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps - XX:+PrintGCDateStamps -Xmx1024m -Dhadoop.security.logger=INFO,DRFAS -Dmapred.audit.logger=INFO,MRAUDIT - Dhadoop.mapreduce.jobsummary.logger=INFO,JSA ${HADOOP_JOBTRACKER_OPTS}" HADOOP_TASKTRACKER_OPTS="-server -Xmx1024m -Dhadoop.security.logger=ERROR,console -Dmapred.audit.logger=ERROR,console ${HADOOP_TASKTRACKER_OPTS}" SHARED_HADOOP_NAMENODE_OPTS="-server -
Filesystem Considerations for Embedded Devices ELC2015 03/25/15
Filesystem considerations for embedded devices ELC2015 03/25/15 Tristan Lelong Senior embedded software engineer Filesystem considerations ABSTRACT The goal of this presentation is to answer a question asked by several customers: which filesystem should you use within your embedded design’s eMMC/SDCard? These storage devices use a standard block interface, compatible with traditional filesystems, but constraints are not those of desktop PC environments. EXT2/3/4, BTRFS, F2FS are the first of many solutions which come to mind, but how do they all compare? Typical queries include performance, longevity, tools availability, support, and power loss robustness. This presentation will not dive into implementation details but will instead summarize provided answers with the help of various figures and meaningful test results. 2 TABLE OF CONTENTS 1. Introduction 2. Block devices 3. Available filesystems 4. Performances 5. Tools 6. Reliability 7. Conclusion Filesystem considerations ABOUT THE AUTHOR • Tristan Lelong • Embedded software engineer @ Adeneo Embedded • French, living in the Pacific northwest • Embedded software, free software, and Linux kernel enthusiast. 4 Introduction Filesystem considerations Introduction INTRODUCTION More and more embedded designs rely on smart memory chips rather than bare NAND or NOR. This presentation will start by describing: • Some context to help understand the differences between NAND and MMC • Some typical requirements found in embedded devices designs • Potential filesystems to use on MMC devices 6 Filesystem considerations Introduction INTRODUCTION Focus will then move to block filesystems. How they are supported, what feature do they advertise. To help understand how they compare, we will present some benchmarks and comparisons regarding: • Tools • Reliability • Performances 7 Block devices Filesystem considerations Block devices MMC, EMMC, SD CARD Vocabulary: • MMC: MultiMediaCard is a memory card unveiled in 1997 by SanDisk and Siemens based on NAND flash memory. -
Linux Journal | System Administration Special Issue | 2009
Cfengine VNC Billix Zenoss Thin Clients MySQL Heartbeat ™ SPECIAL SYSTEM ADMINISTRATION ISSUE Since 1994: The Original Magazine of the Linux Community 2009 | Supplement Issue | www.linuxjournal.com MAY THE SOURCE BE WITH YOU Billix: the Sysadmin Toolkit for Your Pocket Authentication with Fedora Directory Server Remote Desktop Administration with OpenSSH or VNC Manage Configuration Files with Cfengine Setting Up a PXE Boot Server Network Monitoring with Zenoss SPECIAL SYSTEM CONTENTS ADMINISTRATION ISSUE 5 SPECIAL_ISSUE.TAR.GZ 26 PXE MAGIC: FLEXIBLE System Administration: Instant NETWORK BOOTING WITH Gratification Edition MENUS Shawn Powers What if you never had to carry around an install or rescue CD 6 CFENGINE FOR again? Set up a PXE boot server ENTERPRISE with menus and put them all on CONFIGURATION the network. MANAGEMENT Kyle Rankin How to use cfengine to manage configuration files across large 30 CREATING VPNS WITH 17 ZENOSS numbers of machines. IPSEC AND SSL/TLS Scott Lackey The two most common and current techniques for creating VPNs. 10 SECURED REMOTE Rami Rosen Linux Journal DESKTOP/APPLICATION SESSIONS 34 MYSQL 5 STORED 2009 Lineup Different ways to control a Linux PROCEDURES: RELIC OR system over a network. REVOLUTION? JANUARY Mick Bauer Do MySQL 5 Stored Procedures Security produce tiers of joy or sorrow? FEBRUARY Guy Harrison Web Development 38 GETTING STARTED WITH MARCH Desktop HEARTBEAT Availability in a heartbeat. APRIL Daniel Bartholomew System Administration 14 BILLIX: A SYSADMIN’S MAY SWISS ARMY KNIFE 42 FEDORA DIRECTORY Cool Projects SERVER: THE EVOLUTION Build a toolbox in your pocket by JUNE installing Billix on that spare USB key. -
Linux System Administration
Linux System Administration Jonathan Quick Hartebeesthoek Radio Astronomy Observatory Goals • Help you to understand how Linux starts up, keeps running, and shuts down • Give confidence in dealing with hardware and software failures • Give an overview of what you can configure and how • Show you where to find more information when you need it • For the field system and Mark5’s 2 Basic Linux Concepts • Linux Kernel – Base monolithic kernel + loadable modules – Gives standardized access to underlying hardware • Linux System / "Distribution" – Kernel + lots of software – Adds both system and application level software to the system • Background processes ("daemons") 3 System Modifications • In order to do any system-wide changes you usually have to be logged in as 'root‘ – Or have root privileges • There are a number of approaches for this – Log in as user “root” – Execute “su –” from the present user account – Execute the command directly with “sudo” • E.g. “sudo tail /var/log/kern.log” 4 Logging in as 'root' • You can change to a virtual console (Ctrl-Alt- F1) and login normally or use 'su -' • 'root' can override all permissions, start and stop anything, erase hard drives,... – So please be careful with disk names and similar! – You can browse and check many (if not most of the) things as a normal user (like 'oper'). 5 Sudo • Sudo is a program designed to allow a sysadmin to give limited root privileges to users and log root activity. • The basic philosophy is to give as few privileges as possible but still allow people to get their work -
Altavault Cloud Integrated Storage Command-Line Reference Guide
NetApp® AltaVault® Cloud Integrated Storage 4.2.1 Command-Line Reference Guide NetApp, Inc. Telephone: +1 (408) 822-6000 Part number: 215-11346_A0 495 East Java Drive Fax: + 1 (408) 822-4501 August 2016 Sunnyvale, CA 94089 Support telephone: +1(888) 463-8277 U.S. Web: www.netapp.com Feedback: [email protected] Contents Beta Draft Contents Chapter 1 - Using the Command-Line Interface ......................................................................................3 Connecting to the CLI ......................................................................................................................................3 Overview of the CLI.........................................................................................................................................4 Entering Commands .........................................................................................................................................5 Accessing CLI Online Help..............................................................................................................................5 Error Messages .................................................................................................................................................5 Command Negation..........................................................................................................................................5 Running the Configuration Wizard...................................................................................................................6 -
Administración Servidores Linux Paso a Paso
1 Facultad de Ingeniería Mecánica – Universidad Nacional de Ingeniería Administración Servidores Linux Paso a Paso Configuración Servidor Multifunción + Vmware Server 2 (Ver. 1.3) Universidad Nacional de Ingeniería – Facultad de Ingeniería Mecánica - INFOUNI Centro de Cómputo INFOUNI 2 Facultad de Ingeniería Mecánica – Universidad Nacional de Ingeniería Administración Servidores Linux Paso a Paso L. Muga Linux Registered User # 487284 Versión 1.3 Software: Debian 4 Linux, Debian 5 Linux, VMware Server 2.0. Bajo Licencia Creative Commons: Reconocimiento - No comercial 2.5 Perú Usted es libre de: Copiar, Distribuir, Comunicar públicamente la obra y realizar Obras Derivadas bajo las condiciones siguientes: Reconocimiento: Debe reconocer los créditos de la obra de la manera especificada por el autor o licenciante. No comercial: No puede utilizar esta obra para fines comerciales. Alguna de estas condiciones puede no aplicarse si se obtiene el permiso del titular de los derechos de autor. Nada en esta licencia menoscaba o restringe los derechos morales del autor. Windows XP, el logotipo de Windows y VMware son marcas registradas de Microsoft Corporation y VMware Inc. Composición: OpenOffice Versiones: Versión 1.3 : Revisión ortográfica, edición de capítulos anteriores, publicación de capítulo 18 Versión 1.2 : Revisión ortográfica, edición de capítulos anteriores, publicación de capítulos 15, 16 y 17. Versión 1.1 : Revisión ortográfica, publicación de capítulo 14. Versión 1.0 : Publicación del manual. Puede encontrar la última versión del manual en la siguiente dirección: http://issuu.com/nemesisx666. Centro de Cómputo INFOUNI 3 Facultad de Ingeniería Mecánica – Universidad Nacional de Ingeniería Indice General 1. Instalación y configuración de un servidor multifunción 5 1.1 Requisitos de hardware 1.2 Instalando Debian Etch y Actualización a Lenny 1.3 Instalando Debian Lenny 1.4 Antes de empezar 1.5 Configuración de red 1.6 Configuración básica de repositorios 1.7 Instalación de paquetes 1.8 Paquetes para el desarrollo del manual 2. -
Isolation File Systems
Physical Disentanglement in a Container-Based File System Lanyue Lu, Yupu Zhang, Thanh Do, Samer AI-Kiswany Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau University of Wisconsin Madison Motivation Isolation in various subsystems ➡ resources: virtual machines, Linux containers ➡ security: BSD jail, sandbox ➡ reliability: address spaces File systems lack isolation ➡ physical entanglement in modern file systems Three problems due to entanglement ➡ global failures, slow recovery, bundled performance Global Failures Definition ➡ a failure which impacts all users of the file system or even the operating system Read-Only ➡ mark the file system as read-only ➡ e.g., metadata corruption, I/O failure Crash ➡ crash the file system or the operating system ➡ e.g., unexpected states, pointer faults Ext3 200 Read-Only Crash 150 100 50 Number of Failure Instances 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Linux 3.X Versions Ext4 Read-Only Crash 400 350 300 250 200 150 100 50 Number of Failure Instances 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Linux 3.X Versions Slow Recovery File system checker ➡ repair a corrupted file system ➡ usually offline Current checkers are not scalable ➡ increasing disk capacities and file system sizes ➡ scan the whole file system ➡ checking time is unacceptably long Scalability of fsck on Ext3 Ext3 1007 1000 800 723 600 476 400 Fsck Time (s) 231 200 0 200GB 400GB 600GB 800GB File-system Capacity Bundled Performance Shared transaction ➡ all updates share a single transaction ➡ unrelated workloads affect each other Consistency guarantee -
Linux System Administration
Linux System Administration Jonathan Quick, Hartebeesthoek Radio Astronomy Observatory Ari Mujunen, Metsähovi Radio Observatory Linux Startup and Shutdown Managing Hard Disks, Partitions, Backups Rescuing a Failing PC / System Modifying Configuration Adding/Removing Packages 1 Goals Help you to understand how Linux starts up, keeps running, and shuts down Give confidence in dealing with hardware and software failures Give an overview of what you can configure and how Show you where to find more information when you need it 2 Basic Linux Concepts Linux Kernel Base monolithic kernel + loadable modules Gives standardized access to underlying hardware Linux System / "Distribution" Kernel + lots of software Adds both system and application level software to the system Background processes ("daemons") 3 Logging in as 'root' In order to do any system-wide changes you usually have to be logged in as 'root' You can change to a virtual console (Ctrl-Alt- F1) and login normally or use 'su -' 'root' can override all permissions, start and stop anything, erase hard drives,... So please be careful with disk names and similar! You can browse and check many (if not most of the) things as a normal user (like 'oper'). 4 Getting System Information ps axf, top; kill, kill -9 free df, mount netstat -an, ifconfig, route -n w, who cat /proc/cpuinfo (and others) 5 Linux PC-Level Startup PC ROM BIOS initializes hardware and boots a Master Boot Record (MBR) From a floppy, hard disk, CD-ROM, ... That MBR contains LILO, the Linux Loader -
File System and Scheduling Utilities (FSSU)
Preliminary Specification Systems Management: File System and Scheduling Utilities (FSSU) RELIM P I N A R Y [This page intentionally left blank] X/Open Preliminary Specification Systems Management: File System and Scheduling Utilities (FSSU) X/Open Company Ltd. October 1995, X/Open Company Limited All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owners. X/Open Preliminary Specification Systems Management: File System and Scheduling Utilities (FSSU) ISBN: 1-85912-145-4 X/Open Document Number: P521 Published by X/Open Company Ltd., U.K. Any comments relating to the material contained in this document may be submitted to X/Open at: X/Open Company Limited Apex Plaza Forbury Road Reading Berkshire, RG1 1AX United Kingdom or by Electronic Mail to: [email protected] ii X/Open Preliminary Specification Contents Chapter 1 Introduction............................................................................................... 1 1.1 Core Facilities .............................................................................................. 1 1.2 NFS Feature Group..................................................................................... 1 Chapter 2 Scheduling Management .................................................................. 3 cron................................................................................................................... -
Maintaining a File System File System Integrity Utility: Fsck -P [Filesystem]
Maintaining a File System File System Integrity utility: fsck -p [fileSystem] fsck (file system check) scans the specified file systems and checks them for consistency. The kind of consistency errors that can exist include: • A block is marked as free in the bitmap but is also referenced from an inode. • A block is marked as used in the bitmap but is never referenced from an inode. • More than one inode refers to the same block. • An invalid block number. • An inode's link count is incorrect. • A used inode is not referenced from any directory. 1 file system integrity fsck -p [fileSystem] If the -p option is used, fsck automatically corrects any errors that it finds. Without the -p option, it prompts the user for confirmation of any corrections that it suggests. If fsck finds a block that is used but is not associated with a named file, it connects it to a file whose name is equal to the block's inode number in the "/lost+found" directory. If no file systems are specified, fsck checks the standard file systems listed in "/etc/fstab." Linux has specialized fsck programs for different types of file systems. For example, when checking an ext2 or ext3 file system, fsck act as a front-end to e2fsck, which is the program that actually checks the file system. 2 Display disk statistics My disk is full, my files are not saved, why?!@#$ du -- display disk usage displays the number of kB that are allocated to each of the specified filenames. If a filename refers to a directory, its files are recursively described -h option displays more human-readable