UNIX Linux BSD Here are my notes on performance tuning of Linux operating systems

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Summary Linux began as a port of uNIX to Intel computers by a band of "hackers" led by Linus Torvalds in Finland. Linux was first released in 1991 under the GNU project General Public License (GPL). The graphical desktop is provided by an X client known as a window manager, or a desktop environment such as GNOME or KDE. GRUB (Grand Unified Boot) loads initial logic to bring up a machine. YUM (Yellowdog Update Modifier) manages software libraries. The Linux foundation has a FREE intro class: https://courses.edx.org/course_modes/choose/course-v1:LinuxFoundationX+LFS101x.2+1T2015/# Linux is the core. A Linux distribution is what people install.

Portals: Linux HQ Woven Goods for Linux Linux.com About.com guide Juergen Haas offers well-organized content among massive ads. Linux Webring Linux Links Linux Weekly News Just Linux forums IT Toolbox Linux World conferences Community.Java.Net/linux

Distributions These complete operating systems (among many distributions) are based on the Linux kernel Assn. Company Product - Annual Cost Notes Red Hat Linux Fedora for Free Enterprise Desktop: $179, Intel x86 Servers: $349, $1499 HCL United Linux (v1.0 in November 2002) SCO Caldera eDesktop OpenLinux 3.1 Sueing for UNIX they bought from Novell who bought from AT&T S.u.S.E. Linux 3.0 Enterprise $749 Est. 1992 Certified for Oracle & SAP Turbo Linux - the leader in Asia Pacific Conectiva - - Mandrake 8.2 Considered the most newbie-friendly. Includes Star Office Corel - - Linux 8.1 for UNIX veterans. Uses pkgtool. Austrumi A "business card size (50MB)" bootable Live CD dist. GNU/Linux 3.0 Kernel independent WinLinux - Installs directly on (and shares diskspace with) Windows PCs for no HD repartitioning Gentoo - "Portage" metadistribution to "emerge" optimized builds. using BSD style ports.

Download free from: ibiblio's Linux Distribution metalb.unc.edu cdrom.com Order CD's through the mail: Linux Central Linux Mall The Linux Kernel by David A Rusling which

Features Linux has all the features you would expect in a modern fully-fledged Unix, including true multitasking, virtual memory, shared libraries, demand loading, shared copy-on-write executables, proper memory management and TCP/IP networking." linux.redhat comp.os.linux.admin comp.os.linux.redhat linuxdoc.org has a mix of cookbook-style help guides as well as more complete explanations. linuxnewbie.org/ has help files. everythinglinux.org

Linux Documentation Project aims to create the canonical set of free Linux documentation. offers multi-lingual how-tos, topical FAQ, longer Guides Linux Reference Guide by InformIT Host Bill Ball, co-author with Hoyt Duff of $35 Red Hat Linux 9 Unleashed (SAMS: May 8, 2003) Linux User's Guide by Larry Greenfield System Administrators' Guide by Lars Wirzenius, Joanna Oja, Stephen Stafford, and Alex Weeks Network Administrators' Guide by Olaf Kirch Linux ISO.org

Installation For machines without a bootable CDROM, RedHat provides diskettes containing the RAWRITE.exe DOS program in the dosutils directory. To create an installation diskette from /images/boot.img instead of using a bootable CDROM: dd To prepare partitions, use fdisk.exe or the Disk Druid GUI. Red Hat provides the Linux Loader (LILO) boot manager. A mount points refer to the location from which a given partition is accessible.

Redhat8 install CDROM How to by Eric S. Raymond Introduction to Linux - A Hands on Guide by Machtelt Garrels Getting Started Guide Linux Tips by Kevin Cole $35 Complet Linux 6.0 (MacMillan: May, 2003) comes with BootMagic utility to dual boot Windows.

Configuration Red Hat Enterprise Linux has the directory tree (from root): bin dev home lib misc opt root tmp var boot etc initrd lost+found mnt proc sbin usr To avoid "OutOfMemory", "TooManyOpenFiles" errors, and "Unexpected Signal 11" JVM errors, permanently change in opennms.sh file: ulimit -s 8192 ulimit -n 10240 This uses the ulimit BASH built-in command controlling the resources available to a process started by the shell, on systems that allow such control. To display the current settings: ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited file size (blocks, -f) unlimited max locked memory (kbytes, -l) 4 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 stack size (kbytes, -s) 10240 cpu time (seconds, -t) unlimited max user processes (-u) 7168 virtual memory (kbytes, -v) unlimited Note that values are in 1024-byte increments, except for `-t', which is in seconds, `-p', which is in units of 512-byte blocks, and `-n' and `-u', which are unscaled values. If neither `-H' nor `-S' is supplied with a change, both the hard and soft limits are set. Expect a zero return status from the command unless an invalid option is supplied, a non-numeric argument other than unlimited is supplied as a limit, or an error occurs while setting a new limit.

LinuxToday Slashdot.org - for Nerds Red Hat Linux Administration : A Beginner's Guide - Essential Skills Made Easy by Turner, Michael.; Shah, Steve. (London McGraw-Hill Professional, 2003) $60 The Linux Process Manager: The Internals of Scheduling, Interrupts and Signals by John O'Gorman (Hoboken, NJ John Wiley & Sons, Ltd. (UK), 2003) is a line-by-line explanation of the Linux source code kernel.

Programming

Linux Programming Resources at Linoleum by Paul Dwerryhouse Guide to Linux File Command Mastery: A crash course in Linux file commands for the newly initiated by Sheryl Calish

Certifications: Take the Brainbench certification test on Linux Programming & Administration (General), Red Hat 7. Red Hat 9. SuSE. COMPTIA Linux+ Linux Professional Institute (LPIC) is distribution neutral 3 levels: Level 1 Exam 101, 102 Level 2 Exam 201, 202 Level 3 is under developement. Red Hat

$35 Red Hat Linux 9 Bible (Wiley: May, 2003) and previous versions by Christopher Negus is a massive 1104 pages

Configuration

Availability Dates
Hardware	May-2002
OS Software	Feb-2002
HTTP Software	Feb-2002
Network	Oct-2001
Clients	Feb-2002

Hardware
Vendor	Dell
Model	PowerEdge 2650
Processor	2.40 GHz Pentium Xeon
# Processors	2
Primary Cache	12KBI+8KBD on chip
Secondary Cache	512KB ATC
Other Cache	None
Memory	6 GB
Disk Subsystem	5 18GB 10KRPM drives
Disk Controllers	Onboard Adaptec 7899
Other Hardware	2 Dell PowerConnect 5012 4 Nortel ACEswitch 180

Operating System Software
Operating System	Red Hat Linux 7.2
File System	ext2
Other Software	RHSA-2002-028, Intel 4.1.7 driver

Operating System Notes

• ulimit -n 10000, sets number of open files, default 1024
• One NIC bound per logical CPU (Hyper-Threading enabled)
• Each NIC's TX queue length set to 20000 via ifconfig, default 1000
• File systems mounted with "noatime,nodiratime", no inode access time updating
• net.ipv4.nonlocal_bind = 1, allows processes to bind to non-local IP adresses
• net.ipv4.tcp_timestamps = 0, turns TCP timestamp support off, default on
• net.ipv4.tcp_max_tw_buckets = 2000000, sets TCP time-wait buckets pool size, default 180000
• net.ipv4.tcp_rmem = 10000000 10000000 10000000, sets min/default/max TCP read buffer, default 4096 87380 174760
• net.ipv4.tcp_wmem = 10000000 10000000 10000000, sets min/pressure/max TCP write buffer, default 4096 16384 131072
• net.ipv4.tcp_mem = 10000000 10000000 10000000, sets min/pressure/max TCP buffer space, default 31744 32256 32768
• net.ipv4.tcp_sack = 0, turn SACK support off, default on
• net.ipv4.tcp_window_scaling = 0, turn TCP window scaling support off, default on
• net.core.hot_list_length = 300000, maximum number of skb-heads to be cached, default 128
• net.core.rmem_max = 10000000, maximum receive socket buffer size, default 131071
• net.core.wmem_max = 10000000, maximum send socket buffer size, default 131071
• net.core.rmem_default = 10000000, default receive socket buffer size, default 65535
• net.core.wmem_default = 10000000, default send socket buffer size, default 65535
• net.core.wmem_default = 10000000, default send socket buffer size, default 65535
• net.core.optmem_max = 10000000, maximum amount of option memory buffers, default 10240
• net.core.netdev_max_backlog = 300000, number of unprocessed input packets before kernel starts dropping them, default 300
• Kernel parameters:
• idle=poll, idle threads poll reschedule flag, default is to use HLT instruction
• acpismp=force, use ACPI tables for processor information, default MP table

Other Notes

• Dynamic API: Dell-20020204-RHCA.tar.gz
• Kernel config: PE4600.config in Dell-20020204-RHCA.tar.gz

HTTP Software
Vendor	Red Hat
HTTP Software	Red Hat Content Accelerator 2
API	RHCA API
Server Cache	None
Log Mode	Binary CLF

HTTP Software Notes

• One network bound per TUX thread
• net.tux.logging = 1, turns on logging of requests, default 0
• net.tux.cgiroot = /, cgi root check, default /var/www/tux/cgiroot/
• net.tux.cgi_uid = 99, uid 'nobody' for cgi scripts; default -1
• net.tux.cgi_gid = 99, gid 'nobody' for cgi scripts; default -1
• net.tux.max_backlog = 3000, maximum per-listening-socket TCP backlog size, default 2048
• net.tux.generate_etags = 0, don't generate ETag header, default 1
• net.tux.generate_last_mod = 0, don't generate Last-Modified header, default 0
• net.tux.noid = 1, suppress the Server id string, default 0

Network
# of Controllers	4
Network Controllers	3 Intel PRO/1000 XT, 1 Broadcom 5701 LOM
# of Nets	4
Type of Nets	Gigabit Ethernet
Network Speed	1 Gb/s
MSL (sec)	30 (Non RFC1122)
Time-Wait (sec)	60 (Non RFC1122)
MTU	1500

Clients
# of Clients	16
Model	Dell Precision 410
Processor	450MHz Pentium II
# of Processors	2
Memory	128MB
Network Controller	3Com 3C985B-SX
Operating System	Red Hat Linux 7.2
Compiler	gcc 2.96

Client Notes

• net.ipv4.ip_local_port_range = 1024 65535

Benchmark Configuration
Requested Connections	4130
Fileset Size (MB)	13337.04

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Notes

SUT Notes

• 1 disk for OS and logs
• 4 disk software RAID0 stripe for fileset

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