Red Hat Enterprise Linux 5.0.0 Red Hat Enterprise Linux Deployment Guide Red Hat Enterprise Linux 5.0.0: Red Hat Enterprise Linux De- ployment Guide Copyright © 2007 Red Hat, Inc. This Deployment Guide documents relevant information regarding the deployment, configura- tion and administration of Red Hat Enterprise Linux 5.0.0. 1801 Varsity Drive Raleigh, NC 27606-2072 USA Phone: +1 919 754 3700 Phone: 888 733 4281 Fax: +1 919 754 3701 PO Box 13588 Research Triangle Park, NC 27709 USA Documentation-Deployment Copyright © 2007 by Red Hat, Inc. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, V1.0 or later (the latest version is presently available at ht- tp://www.opencontent.org/openpub/). Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copy- right holder. Distribution of the work or derivative of the work in any standard (paper) book form for commercial purposes is prohib- ited unless prior permission is obtained from the copyright holder. Red Hat and the Red Hat "Shadow Man" logo are registered trademarks of Red Hat, Inc. in the United States and other countries. All other trademarks referenced herein are the property of their respective owners. The GPG fingerprint of the [email protected] key is: CA 20 86 86 2B D6 9D FC 65 F6 EC C4 21 91 80 CD DB 42 A6 0E Table of Contents Introduction ............................................................................................................ xxii 1. Document Conventions ............................................................................... xxii 2. Send in Your Feedback ............................................................................... xxv I. File Systems ........................................................................................................... 1 1. File System Structure ..................................................................................... 2 1. Why Share a Common Structure? ........................................................... 2 2. Overview of File System Hierarchy Standard (FHS) ................................. 2 2.1. FHS Organization ........................................................................ 2 3. Special File Locations Under Red Hat Enterprise Linux ............................ 6 2. The ext3 File System ...................................................................................... 7 1. Features of ext3 ..................................................................................... 7 2. Creating an ext3 File System .................................................................. 7 3. Converting to an ext3 File System ........................................................... 8 4. Reverting to an ext2 File System ............................................................. 9 3. The proc File System ....................................................................................10 1. A Virtual File System .............................................................................10 1.1. Viewing Virtual Files ...................................................................10 1.2. Changing Virtual Files ................................................................11 2. Top-level Files within the proc File System .............................................11 2.1. /proc/apm ..................................................................................11 2.2. /proc/buddyinfo ..........................................................................12 2.3. /proc/cmdline .............................................................................12 2.4. /proc/cpuinfo ..............................................................................13 2.5. /proc/crypto ................................................................................14 2.6. /proc/devices .............................................................................14 2.7. /proc/dma ..................................................................................15 2.8. /proc/execdomains .....................................................................15 2.9. /proc/fb ......................................................................................15 2.10. /proc/filesystems ......................................................................15 2.11. /proc/interrupts .........................................................................16 2.12. /proc/iomem .............................................................................17 2.13. /proc/ioports .............................................................................17 2.14. /proc/kcore ...............................................................................18 2.15. /proc/kmsg ...............................................................................18 2.16. /proc/loadavg ...........................................................................18 2.17. /proc/locks ...............................................................................18 2.18. /proc/mdstat .............................................................................19 2.19. /proc/meminfo ..........................................................................19 2.20. /proc/misc ................................................................................21 2.21. /proc/modules ..........................................................................21 2.22. /proc/mounts ............................................................................22 2.23. /proc/mtrr .................................................................................23 2.24. /proc/partitions .........................................................................23 2.25. /proc/pci ...................................................................................23 2.26. /proc/slabinfo ...........................................................................24 iv Red Hat Enterprise Linux 5.0.0 2.27. /proc/stat ..................................................................................25 2.28. /proc/swaps .............................................................................26 2.29. /proc/sysrq-trigger ....................................................................26 2.30. /proc/uptime .............................................................................26 2.31. /proc/version ............................................................................27 3. Directories within /proc/ .........................................................................27 3.1. Process Directories ....................................................................27 3.2. /proc/bus/ ..................................................................................29 3.3. /proc/driver/ ...............................................................................30 3.4. /proc/fs ......................................................................................30 3.5. /proc/ide/ ...................................................................................30 3.6. /proc/irq/ ....................................................................................32 3.7. /proc/net/ ...................................................................................32 3.8. /proc/scsi/ ..................................................................................33 3.9. /proc/sys/ ...................................................................................35 3.10. /proc/sysvipc/ ...........................................................................46 3.11. /proc/tty/ ..................................................................................47 4. Using the sysctl Command ....................................................................47 5. Additional Resources ............................................................................48 5.1. Installed Documentation .............................................................48 5.2. Useful Websites .........................................................................48 4. Redundant Array of Independent Disks (RAID) ...............................................49 1. What is RAID? ......................................................................................49 2. Who Should Use RAID? ........................................................................49 3. Hardware RAID versus Software RAID ...................................................49 3.1. Hardware RAID ..........................................................................49 3.2. Software RAID ...........................................................................50 4. RAID Levels and Linear Support ............................................................50 5. Configuring Software RAID ....................................................................51 5.1. Creating the RAID Partitions .......................................................52 5.2. Creating the RAID Devices and Mount Points ..............................55 5. Swap Space .................................................................................................61 1. What is Swap Space? ...........................................................................61 2. Adding Swap Space ..............................................................................61 2.1. Extending Swap on an LVM2 Logical Volume ..............................62 2.2. Creating an LVM2 Logical Volume for Swap ................................62 2.3. Creating a Swap File ..................................................................63