Fractional Futurist

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Category: Linux

  • Fixing the Heartbleed vulnerability on CentOS

    Fixing the Heartbleed vulnerability on CentOS

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    While the popular media have jumped on the Heartbleed Bug as if the sky were falling causing mass panic, it is actually quick and easy to fix for us CentOS users. Red Hat released a patched version of OpenSSL on 8th April and it has already filtered down to the CentOS updates repository, so all…

  • Installing CentOS packages on Red Hat Enterprise Linux

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    At the weekend I got into a discussion with Andy Stanford-Clark and Richard Appleby on Twitter troubleshooting basic application installation in Red Hat Enterprise Linux (like Pidgin). Not finding a solution later began to plague me, I grabbed a copy of RHEL and installed it on a Virtual Machine to solve the problem. If you’re interested in the history of the Red…

  • A brief history of Red Hat, Fedora and CentOS

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    The Linux ecosystem can be confusing because of the shear amount of choice available. I’ve always been a Red Hat guy and have spent a significant amount of my life staring at it’s installer. Don’t get me wrong, I’ve used just about every other distribution out there as well as create my own one. This…

  • Supermicro AOC-SASLP-MV8: DRIVER_TIMEOUT

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    I have been using the Supermicro AOC-SASLP-MV8 host bus adapter on quite a few Linux machines recently.  Supermicro/Marvell only provide stable drivers for Windows and a select few (outdated) Linux distributions.  I had to rely on the open-source support in the drivers/scsi/mvsas tree of the Linux kernel. Running this card with 8 x 2TB hard…

  • Open MPI Master & Servant Example – BogoMips

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    In yesterdays post I introduced a simple ‘master & servant’ technique where I used the rank-0 node to collate results from all the other nodes. To do this I used the methods MPI_Send and MPI_Recv to send/recv 128-byte MPI_CHAR strings. Today I am extending the example by sending/receiving MPI_FLOAT‘s to demonstrate that native C/C++ numerical…

  • An Open MPI Master & Servant Example

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    Building on the Getting started… post from last week I’ve knocked up a quick example showing one way to get your MPI processes to communicate with one another. master_servant.c: #include <stdio.h> #include <mpi.h> #include <unistd.h> int main(int argc, char *argv[]) { int numprocs, rank, namelen; char processor_name[MPI_MAX_PROCESSOR_NAME]; MPI_Init(&argc, &argv); MPI_Comm_size(MPI_COMM_WORLD, &numprocs); MPI_Comm_rank(MPI_COMM_WORLD, &rank); MPI_Get_processor_name(processor_name, &namelen);…

  • Getting started with Open MPI on Fedora

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    Recently rediscovered the world of parallel computing after wondering what to do with a bunch of mostly idle Linux boxes, all running various versions of Fedora Core Linux. I found this guide particularly useful and decided to elaborate on the subject here. Background Open MPI is an open-source implementation of the Message Passing Interface which…

  • Hauppauge WinTV-NOVA-HD-S2 working on Fedora Rawhide

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    Long story short, I installed Fedora Core 10, enabled fedora-rawhide.repo and upgraded to Rawhide (17th Feb ’09), giving the following post install/upgrade: acl-2.2.47-3.fc10.i386 apr-1.3.3-3.fc11.i386 apr-util-1.3.4-2.fc11.i386 apr-util-ldap-1.3.4-2.fc11.i386 attr-2.4.43-1.fc10.i386 audit-libs-1.7.11-2.fc11.i386 audit-libs-python-1.7.11-2.fc11.i386 authconfig-5.4.7-1.fc11.i386 basesystem-10.0-1.noarch bash-4.0-0.4.rc1.fc11.i386 binutils-2.19.51.0.2-12.fc11.i386 bzip2-1.0.5-3.fc10.i386 bzip2-libs-1.0.5-3.fc10.i386 ca-certificates-2008-7.noarch checkpolicy-2.0.16-3.fc10.i386 chkconfig-1.3.41-1.i386 compat-db45-4.5.20-5.fc10.i386 ConsoleKit-libs-0.3.0-3.fc11.i386 coreutils-7.0-7.fc11.i386 cpio-2.9.90-3.fc11.i386 cpp-4.4.0-0.19.i386 cracklib-2.8.13-2.i386 cracklib-dicts-2.8.13-2.i386 cronie-1.2-7.fc10.i386 crontabs-1.10-28.fc11.noarch curl-7.18.2-9.fc11.i386 cyrus-sasl-lib-2.1.22-21.fc11.i386 db4-4.7.25-9.fc11.i386 db4-utils-4.7.25-9.fc11.i386 dbus-1.2.4.4permissive-1.fc11.i386 dbus-glib-0.80-1.fc11.i386 dbus-libs-1.2.4.4permissive-1.fc11.i386 dbus-python-0.83.0-4.fc11.i386…

  • DVB Support for the Videolan Client (VLC) on Fedora Core 5

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    The version of the Videolan Client (VLC) for Fedora Core 5 from freshrpms does not include DVB support. [foo@localhost ~]$ vlc –program 4704 dvb:12207000:0:3:27500000 VLC media player 0.8.5 Janus status change: ( new input: dvb:12207000:0:3:27500000 ) status change: ( audio volume: 256 ) status change: ( play state: 1 ) [00000295] main input error: no…

  • What not to do when you’ve installed sshdfilter

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    sshdfilter is a great tool which monitors system logs for repetitive failed login attempts and actively updates iptables to block offending ip addresses. However, there is a slight shortfall it its design as there are no exceptions to its blocking rules as I found this morning: Subject: sshdfilter event for 127.0.0.1, Too many password guesses,…

  • Fedora Core 5 yum.conf

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    Just a quick snippet of my /etc/yum.conf file which includes the ATrpms and FreshRpms repositories. [main] cachedir=/var/cache/yum keepcache=0 debuglevel=2 logfile=/var/log/yum.log pkgpolicy=newest distroverpkg=redhat-release tolerant=1 exactarch=1 obsoletes=1 gpgcheck=1 plugins=1 metadata_expire=1800 [atrpms] name=Fedora Core $releasever – $basearch – ATrpms baseurl=http://dl.atrpms.net/fc$releasever-$basearch/atrpms/stable [freshrpms] name=Fedora Linux $releasever – $basearch – freshrpms baseurl=http://ayo.freshrpms.net/fedora/linux/$releasever/$basearch/freshrpms

  • Trac – Emptying a Wiki database

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    A quick bit of shell magic to empty a Trac wiki database in a freshly installed Trac environment. In this example /var/www/html/trac is assumed to be the Trac environment you created with trac-admin. $ for page in `trac-admin /var/www/html/trac wiki list | cut -d’ ‘ -f1 | grep “^[A-Z]” | grep -v “Title”`; do trac-admin…

  • Fedora Core 5 on VMWare 5.5

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    Fedora Core 5 was released yesterday, I attempted to upgrade my existing Fedora Core 4 installation in VMWare Workstation 5.5.0 and encountered a problem. Fedora isn’t automatically detecting the VMWare SCSI device, it presents a warning that there were no hard drives were detected. I found you can resolve this by manually adding the BusLogic…

  • Update: TI 7×21 FlashMedia/SD Host Controller (104C:8033 & 104C:8034)

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    Bit of an update, my previous post is now getting a significant amount of traffic; in fact it’s my hottest post yet! Progress over at http://tifmxx.berlios.de/ – I downloaded the latest revision of this driver and it appears to be going through re-structuring, still not-functional I am afraid. However, a month since contacting TI I…

  • Using sshdfilter to secure an SSH server

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    Since moving my OpenSSH server down to its standard port number I have been hit daily by service scanning software and brute force password attacks. Gerry pointed out that sshdfilter can help. sshdfilter blocks the frequent brute force attacks on ssh daemons, it does this by directly reading the sshd logging output and generating iptables…