Linux System Administration Paul Cobbaut Linux System Administration Paul Cobbaut lt-1.9 Publication date Mon 26 May 2014 01:00:55 AM CEST Abstract This book is meant to be used in an instructor-led training. For self-study, the intent is to read this book next to a working Linux computer so you can immediately do every subject, practicing each command. This book is aimed at novice Linux system administrators (and might be interesting and useful for home users that want to know a bit more about their Linux system). However, this book is not meant as an introduction to Linux desktop applications like text editors, browsers, mail clients, multimedia or office applications. More information and free .pdf available at http://linux-training.be . Feel free to contact the author: • Paul Cobbaut: [email protected], http://www.linkedin.com/in/cobbaut Contributors to the Linux Training project are: • Serge van Ginderachter: [email protected], build scripts and infrastructure setup • Ywein Van den Brande: [email protected], license and legal sections • Hendrik De Vloed: [email protected], buildheader.pl script We'd also like to thank our reviewers: • Wouter Verhelst: [email protected], http://grep.be • Geert Goossens: [email protected], http://www.linkedin.com/in/ geertgoossens • Elie De Brauwer: [email protected], http://www.de-brauwer.be • Christophe Vandeplas: [email protected], http://christophe.vandeplas.com • Bert Desmet: [email protected], http://blog.bdesmet.be • Rich Yonts: [email protected], Copyright 2007-2014 Paul Cobbaut Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled 'GNU Free Documentation License'. Table of Contents I. process management .............................................................................................................. 1 1. introduction to processes ............................................................................................. 3 1.1. terminology ...................................................................................................... 4 1.2. basic process management ................................................................................... 5 1.3. signalling processes ............................................................................................ 9 1.4. practice : basic process management .................................................................... 12 1.5. solution : basic process management .................................................................... 13 2. process priorities ....................................................................................................... 15 2.1. priority and nice values ..................................................................................... 16 2.2. practice : process priorities ................................................................................. 19 2.3. solution : process priorities ................................................................................. 20 3. background jobs ....................................................................................................... 22 3.1. background processes ........................................................................................ 23 3.2. practice : background processes .......................................................................... 25 3.3. solution : background processes .......................................................................... 26 II. disk management ............................................................................................................... 28 4. disk devices .............................................................................................................. 31 4.1. terminology ..................................................................................................... 32 4.2. device naming ................................................................................................. 34 4.3. discovering disk devices .................................................................................... 35 4.4. erasing a hard disk ........................................................................................... 40 4.5. advanced hard disk settings ................................................................................ 41 4.6. practice: hard disk devices ................................................................................. 42 4.7. solution: hard disk devices ................................................................................. 43 5. disk partitions ........................................................................................................... 45 5.1. about partitions ................................................................................................ 46 5.2. discovering partitions ........................................................................................ 47 5.3. partitioning new disks ....................................................................................... 49 5.4. about the partition table ..................................................................................... 51 5.5. practice: partitions ............................................................................................ 52 5.6. solution: partitions ............................................................................................ 53 6. file systems ............................................................................................................... 54 6.1. about file systems ............................................................................................ 55 6.2. common file systems ........................................................................................ 56 6.3. putting a file system on a partition ...................................................................... 59 6.4. tuning a file system .......................................................................................... 60 6.5. checking a file system ....................................................................................... 61 6.6. practice: file systems ........................................................................................ 62 6.7. solution: file systems ........................................................................................ 63 7. mounting .................................................................................................................. 64 7.1. mounting local file systems ................................................................................ 65 7.2. displaying mounted file systems .......................................................................... 66 7.3. from start to finish ........................................................................................... 68 7.4. permanent mounts ............................................................................................ 69 7.5. securing mounts ............................................................................................... 70 7.6. mounting remote file systems ............................................................................. 71 7.7. practice: mounting file systems ........................................................................... 72 7.8. solution: mounting file systems ........................................................................... 73 8. troubleshooting tools ................................................................................................. 75 8.1. lsof ................................................................................................................ 76 8.2. fuser .............................................................................................................. 77 8.3. chroot ............................................................................................................ 78 8.4. iostat .............................................................................................................. 79 8.5. iotop .............................................................................................................. 79 8.6. practice: troubleshooting tools ............................................................................ 80 iv Linux System Administration 8.7. solution: troubleshooting tools ............................................................................ 81 9. introduction to uuid's ................................................................................................ 82 9.1. about unique objects ......................................................................................... 83 9.2. tune2fs ........................................................................................................... 83 9.3. uuid ............................................................................................................... 83 9.4. uuid in /etc/fstab .............................................................................................. 84 9.5. uuid as a boot device ........................................................................................ 85 9.6. practice: uuid and filesystems ............................................................................