Linux University Handbook

autozen

Thu, 15 Apr 2010 15:18:57 -0400

AutoZen is a software 'brain machine' for Linux. It generates sounds that are meant to cause the brain to temporarily shift to a different dominant frequency and cause the user to experience an altered state of consciousness. It is similar to the devices seen in the 'Sharper Image' catalog and in magazine ads, but the price is a lot more attractive!

bpcp

Thu, 15 Apr 2010 15:18:57 -0400

BPCP bpcp is the best utility for copying files effeciently across the cluster. It is the bproc replacement for rcp and scp. It's syntax is compatable with rcp. Syntax bpcp Both source and destination are specified in the form [:][/]

bpctl

Thu, 15 Apr 2010 15:18:57 -0400

BPCTL bpctl may be used to command a node to enter a new state, or to change permissions to use a node. * bpctl -S -s State may be: * reboot (node will reboot immediatly) * halt (node halts) * unavailable (only root may access the node) * error (only root may access node) * bpctl -v : print software version and exit. * bpctl -h : show command help. * bpctl

bprun

Thu, 15 Apr 2010 15:18:57 -0400

BPSH All non-MPI jobs on slave nodes are executed through bpsh. Though bpsh is really a simple wrapper for the bproc system, it's use and functionality will be documented seperatly here, since the functionality of bproc itself falls more in the scope of advanced programming than everyday use.

bpsh

Thu, 15 Apr 2010 15:18:57 -0400

NAME bpsh - run a command on a remote node SYNOPSIS bpsh -h bpsh -v bpsh nodespec command arguments . bpsh -a command arguments . bpsh -A command arguments . DESCRIPTION bpsh executes command on the nodes given by nodespec. bpsh is designed to operate in a fashion similar to rsh.

bpstat

Thu, 15 Apr 2010 15:18:57 -0400

BPSTAT bpstat is a command line utility which provides status information on the slave nodes in the cluster. Syntax * bpstat -h displays help * bpstat -v display version info * bpstat [] Options: -p display PIDS running on on nodes -a display node IP addresses -l display long status (verbose) -U display continuously updated list

buildroot

Mon, 25 Feb 2008 18:45:58 -0400

Buildroot is a set of makefiles and configurations intended to download and build a series of packages and install them into a target directory. The central package in a buildroot system is uClibc, a lightweight libc designed for use in an embedded environment.

capabilities

Wed, 24 Jan 2007 14:42:15 -0400

Please see Capabilities

chroot

Sat, 13 Jan 2007 12:54:37 -0400

Chroot is largely a neat semantic hack that has come to be expected on Unix systems. Simply, when chroot is called with a pathname, that pathname becomes '/' for the process and it's descendants. Nothing more, nothing less. It is worth noting that since it IS a semantic hack that was never originally envisioned as a security measure, several holes exist in it. It is also notable that many use chroot as a security measure, and it is even becoming part of 'best practices' for some daemons, partic…

chroot_hack

Mon, 15 Jan 2007 05:29:28 -0400

chroot_patch

Thu, 15 Apr 2010 15:18:57 -0400

POSIX Capabilities is a fundamentally sound idea hobbled by silliness that makes the capability system difficult to understand. The concept is to replace the old model of root is god and everyone else isn't with the idea of a process having capabilities. Capabilities can be seen as sub-divided root powers. For example, in the old model, root (UID 0) can bypass file permissions (that is, root is always permitted). In the capabilities model, if a process has CAP_DAC_OVERRIDE, it is always permitt…

cisco

Thu, 15 Apr 2010 15:18:57 -0400

Rate limiting connections on a Cisco 65xx would seem to be a commonly desired configuration, yet documentation on it is a bit sketchy IMHO. Firstly, it's lumped under QoS. While QoS is certainly related, there are reasons to rate limit that have little to do with QoS. That is, a small colo facillity might well wish to rate limit all customers in accordance with contracted bandwidth while having no desire to configure what most would consider QoS (That is segregating traffic by type (such …

cmos

Thu, 15 Apr 2010 15:18:57 -0400

Introduction LinuxBIOS supports a number of configuration options in CMOS. After booting, LinuxBIOS leaves a table in RAM which details the available option values. The table, and the current cmos settings are accessed by cmos_util. cmos_util [-d | -u] [-s] [--image filename]

dvd

Thu, 15 Apr 2010 15:19:02 -0400

The art of mastering a DVD that will actually work in a standalone player includes a lot of complexities. There are many fine tools and some not so fine tools for Linux that help greatly with this process, but they have to be gathered together and in some cases, workarounds are required.

enhancements_to_bind_mounts

Thu, 15 Apr 2010 15:18:57 -0400

enhanced_bind is a modification primarily aimed at making chroot jails easier to set up, more secure, and less wasteful of storage. The first enhancement comes from the Linux vserver project. This adds the ability to make bind mounts nosuid, read-only, nodev, and noexec.

f.l.a.m.e

Thu, 15 Apr 2010 15:18:57 -0400

F.L.A.M.E.™ Fast Linking Associative Memory Engine * Max speed for your database aps * New data mgmt paradigm * Bibliographic search engine Given n freeform data objects... + ADD extensions to Boolean Algebra x MULTIPLY by a Single System Image cluster = Multi-Dimensional Object-Linked Memory Core• Each chained object carries a path linked to the entire information base. • Searches report results instantaneously and with provable scientific accuracy. • Fastest path to any search …

fedora-bproc

Thu, 15 Apr 2010 15:19:00 -0400

This is a brief set of notes on integrating bproc into Fedora core 6 DHCP has a new “feature' (read as BUG). Unless a next-server option is specified (normally the address of the DHCP server), PXE clients will attempt to fetch the pxelinux.cfg from 0.0.0.0 which will naturally fail. Given that the old behavior was the natural default and fetching from 0.0.0.0 is NEVER the right thing, I say it's a big fat bug!

flash

Thu, 15 Apr 2010 15:18:57 -0400

LinuxBIOS Technical Documentation and User Programs Memory Layout LinuxBIOS supports the concept of a primary and a fallback boot image in order to allow updates to a system, all the while minimizing the risk that the system will become unbootable. In most cases, where flash chips are socketed, this is merely a strong convenience; in others where the flash chip is soldered to the board, it is nearly necessity.

jail_system_call

Mon, 15 Jan 2007 05:46:48 -0400

The jail call is inspired by and somewhat modeled on the jail syscall from FreeBSD. Jail brings together the IronPenguin improvements in chroot, bind mounts, etc and adds signal and process isolation. The primary purpose of jail is to allow the creation of extremely lightweight virtual servers that live in a chroot jail.

krd

Thu, 15 Apr 2010 15:18:57 -0400

krd: kcore reader Quick Introduction krd is a rootkit detection utility which scan /proc/kcore for interesting data. Suspicious programs (sk, adore, etc.), worms/backdoors/viruses are detected even if running silently in your kernel. For instance, the ASCII string OSF indicates the ELF infector GMON.A is present.

mirr

Thu, 15 Apr 2010 15:18:57 -0400

Mirroring the Master to the secondary master. The objective is to make the secondary master's filesystem exactly the same as the primary so that in the event of a failover, the system will function as it did prior to the failure. tar is used in order to preserve meta information (owner, date, permissions, etc) of the files. Thus, first the tar archives are created on the master and copied over to the secondary master (node 0). Then, the backup master filesystem partitions are mounted on the s…

mpi

Thu, 15 Apr 2010 15:18:57 -0400

Running Nimbus comes pre-loaded with a slightly modified version of MPICH that knows about bproc. These modifications allow MPI applications to run convieniantly on a Nimbus cluster without a need for various wrapper applications (such as mpirun) The number of processes spawned, and where they are run is controled through environment variables that may be set by the user, or by the maui scheduler through raccoon. In brief, they are:

netcons

Thu, 15 Apr 2010 15:18:57 -0400

Netconsole Introduction Netconsole is a kernel device to redirect normal kernel console messages through layer 2 (ethernet) packets. The intent is to provide better status, and diagnostic feedback while avoiding the expense of a serial concentrator system.

nimbus

Thu, 15 Apr 2010 15:18:57 -0400

Linux Labs – Beowulf Distribution: Codename Nimbus Cluster Management Overview I. Architecture Overview * The Beostat daemon has been replaced with the supermon utilities from LANL - this is a very lightweight /proc based system that uses virtually no system resources; as opposed to its rather onerous predecessor. * Wakinyan Monitor: A graphical monitor that both saves on screen space and has ambient temperature output. * 2.4.19 Linux kernel for cutting-edge stability and latest featur…

nod

Thu, 15 Apr 2010 15:18:57 -0400

Node numbers All nodes in a Nimbus cluster have an associated number. The number of a node is assigned at boot time by bpmaster. In turn, bpmaster determines that number by looking up the slaves MAC address in the node lines of /etc/beowulf/config.

ofs

Thu, 15 Apr 2010 15:18:57 -0400

OFS: OPUS File System (Open Parallel Unified System) The state of filesystems: In spite of advances in clustered and distributed computing, filesystems remain in the dark ages. The primary option for sharing filesystems remains NFS. Development exists in the form of GFS and CODA, but neither really meets requirements. Filesystems remain intimately bound to their block device based backing store. Even with LVM and other techniques to improve the block storage itself, filesystems are not rea…

pine

Sat, 04 Apr 2009 00:13:54 -0400

Because the license for Pine does not allow any binary distribution, Debian, Ubuntu, and probably others make the source package available, but not a ready made binary. To install it, create and cd to a new directory, then: apt-get source pine apt-get build-dep pine apt-get -b source pine This has apt download the source for pine, then install any packages needed to build the package, then build (-b) and install it.

projects

Wed, 24 Jan 2007 14:40:16 -0400

AutoZen : is a software ‘brain machine’ for Linux. F.L.A.M.E.™ : Fast Linking Associative Memory Engine krd : kcore reader ofs : OPUS File System chroot "hack" : on chroot ... capabilities : description of capabilities as implemented in the patch - fscaps patch for the kernel

pyro

Sun, 05 Apr 2009 16:08:48 -0400

FIXME :-) iptables API buildroot bproc 802.11 wireless fedora-bproc postfix info and tools Virtual mail system with postfix on Debian Etch Samba PVenti Install pine on debian and Ubuntu Dvd mastering in Linux

raccoon

Thu, 15 Apr 2010 15:18:57 -0400

Raccoon Raccoon's function is to translate Supermon's s-expression data format into XML required by Ganglia. In addition Raccoon provides a Wiki for the Maui scheduler (NOTE: Wiki is a term for either a user editable web page system, OR a service provided to Maui so that it may gather resource data and launch jobs on a particular system. Wiki in Hawiian = Quick, so many have used it for many different things!). These similar but seperate tasks are performed by a single package to avoid a great…

rebuild

Thu, 15 Apr 2010 15:18:57 -0400

Rebuilding from source RPMs While LinuxLabs does it's best to choose reasonable build options for user applications, sometimes, there is a need to rebuild a package. This document is a brief summary of that process. Detailed information on creating, modifying, and managing RPMs is found in Maximum RPM included here for your convieniance.

slave

Thu, 15 Apr 2010 15:18:57 -0400

The nimbus boot process can be divided broadly into 3 stages. The first stage varies by the type of system while stages two and three are the same for all Nimbus clusters. The stages will be reviewed in order. * Stage 1 Stage 1 begins with power on to the node. In systems with a standard BIOS, stage 1 is a PXE boot. For LinuxBIOS systems, Etherboot is used instead.

speed_test_for_krd_0.1

Thu, 15 Apr 2010 15:18:57 -0400

Scanning speed for krd 0.1 ALGORITHM USED: The algorithm used is very basic and very slow in this prototype version. It reads /proc/kcore file byte by byte, which means it give results after quite some time. The next version will reads by “pages” of data to increase the speed.

start

Tue, 04 May 2010 14:16:11 -0400

Welcome to the LinuxEdu Wiki. This wiki is designed to provide educational information to the linux users and its community. Feel free to promote and contribute. ---------- Documentation * The Linux Handbook A guide for all kinds of linux users

world_soccer_cup

Tue, 04 May 2010 10:46:24 -0400

Today, there is no other sporting event that captures world’s attention like the world soccer cup. FIFA (Fédération Internationale de Football Association) was established on May 21st 1904 in Paris with the authorization of the representatives of France, Belgium, Denmark, Netherlands, Spain, Sweden and Switzerland. The first FIFA Congress held two days later elected Robert Guérin as President. South Africa joined in 1909, Argentina and Chile in 1912 and USA in 1913. The new organization existed …