“Wir feiern 111.111 Facebook Fans und verlosen den CINEMA 3D TV 42LM760S”

Viel Glück

references

• http://en.wikipedia.org/wiki/GlusterFS
• http://backports-master.debian.org/
• http://www.gluster.org/

In the first step I will setup a glusterfs volume

First step – setup a replicated Glusterfs volume

In the first step I will setup a replicated Glusterfs volume on Debian 6.x with on two Debian 6.x server.
The hostnames for my setup are debian01 and debian02. Because I am using an simple test-environment, I have
to add the nodes to the /etc/hosts file.

preparation

10.2.1.251 debian01
10.2.1.255 debian02

I will use the newer Glusterfs version 3.2.4 from Debian Backports:

Add the following line to /etc/apt/sources.list

deb http://backports.debian.org/debian-backports squeeze-backports main

And install Glusterfs

apt-get update
apt-get install glusterfs-server=3.2.4-1~bpo60+1 glusterfs-client=3.2.4-1~bpo60+1

The glusterfs daemon should be started after the installation.

In my example the Glusterfs will use the following directory as the storage on both nodes.

root@debian01 # mkdir -p /export/data
root@debian02 # mkdir -p /export/data

Glusterfs setup

Now add the node debian02 to the storage pool.

root@debian01:~# gluster peer probe debian02
Probe successful

Its not necessary to add the localhost (in this example debian01) to the pool.

The Glusterfs volume will be created with the gluster command

Syntax# gluster volume create NEW-VOLNAME [replica COUNT] [transport tcp | rdma] NEW-BRICK…

For the two nodes replicated volume I used the following command:

root@debian01:/etc/glusterfs# gluster volume create datastore replica 2 transport tcp debian01:/export/data debian02:/export/data/
Creation of volume datastore has been successful. Please start the volume to access data.

I set the following ACL for the volume (access is allowed only from the 10.2.0.0/16 network)

root@debian02:~# gluster volume set test-volume auth.allow 10.2.*
Volume test-volume does not exist
Set volume unsuccessful

Start the created Glusterfs Volume with the following command:

root@debian01:/etc/glusterfs# gluster volume start datastore
Starting volume datastore has been successful

Verify the setup with the following commands / checks:

root@debian02:~# showmount -e debian02
Export list for debian02:
/datastore *

root@debian02:/# gluster volume info
Volume Name: datastore
Type: Replicate
Status: Started
Number of Bricks: 2
Transport-type: tcp
Bricks:
Brick1: debian01:/export/data
Brick2: debian02:/export/data

After stopping the Gusterfs volume, the NFS export should`t be available :

root@debian02:~# gluster volume stop datastore 
Stopping volume will make its data inaccessible. Do you want to continue? (y/n) y
root@debian01:/etc# showmount -e debian01
clnt_create: RPC: Program not registered

Start the Gluserfs volume again:

root@debian02:~# gluster volume start datastore 
Starting volume datastore has been successful

Create a mountpoint for the Glusterfs volume and mount it on both nodes:

root@debian01:/etc# mkdir /mnt/datastore 
root@debian01:/etc# mount -t glusterfs debian01:/datastore /mnt/datastore 
root@debian01:/etc# mount
/dev/sda1 on / type ext3 (rw,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
debian01:/datastore on /mnt/datastore type fuse.glusterfs (rw,allow_other,default_permissions,max_read=131072)

root@debian02:/etc# mkdir /mnt/datastore 
root@debian02:/# mount -t glusterfs debian02:/datastore /mnt/datastore
root@debian02:/# mount
/dev/sda1 on / type ext3 (rw,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
debian02:/datastore on /mnt/datastore type fuse.glusterfs (rw,allow_other,default_permissions,max_read=131072)

Second step – expand a replicated Glusterfs volume

I will expand the Glusterfs volume datastore with two nodes. I will use the hostnames debian03 and debian04 in my example.

Two more nodes?

First I tried to add only one node in my test setup and got the following error.

root@debian02:/# gluster volume add-brick datastore debian03:/export/data
Incorrect number of bricks supplied 1 for type REPLICATE with count 2

And the answer is in the Glusterfs documentation:

Note: When expanding distributed replicated and distributed striped volumes, you need to add a number of bricks that is a multiple of the replica or stripe count. For example, to expand a distributed replicated volume with a replica count of 2, you need to add bricks in multiples of 2 (such as 4, 6, 8, etc.).

preparation

On all four nodes extend the /etc/hosts file with the new nodes debian03 and debian04:

10.2.1.251 debian01
10.2.1.255 debian02
10.2.2.34 debian03
10.2.2.35 debian04

Installation of Glusterfs as with debian01 and debian02

deb http://backports.debian.org/debian-backports squeeze-backports main

And install Glusterfs

apt-get update
apt-get install glusterfs-server=3.2.4-1~bpo60+1 glusterfs-client=3.2.4-1~bpo60+1

root@debian03 # mkdir -p /export/data
root@debian04 # mkdir -p /export/data

expanding the Glusterfs Volume

On debian01 add the new nodes to the storage pool:

root@debian01:/# gluster peer probe debian03
Probe successful

root@debian01:/# gluster peer probe debian04
Probe successful

Expand the volume with the gluster command:

root@debian02:/# gluster volume add-brick datastore debian03:/export/data debian04:/export/data
Add Brick successful

Verify the volume, we should have 3 peer nodes now:

root@debian01:/etc# gluster peer status
Number of Peers: 3

Hostname: debian02
Uuid: cb6ae562-ea21-4c2d-baa2-4c2b2597e18a
State: Peer in Cluster (Connected)

Hostname: debian03
Uuid: 380fda84-b952-4261-af55-27a9d8d1afbc
State: Peer in Cluster (Connected)

Hostname: debian04
Uuid: 65f37919-6f88-48fa-a782-b4292539a9bf
State: Peer in Cluster (Connected)

root@debian01:/etc# gluster volume info
Volume Name: datastore
Type: Distributed-Replicate
Status: Started
Number of Bricks: 2 x 2 = 4
Transport-type: tcp
Bricks:
Brick1: debian01:/export/data
Brick2: debian02:/export/data
Brick3: debian03:/export/data
Brick4: debian04:/export/data

After expanding the volume a rebalancing of the volume data is necessary:

root@debian01:/etc# gluster volume rebalance datastore start

Check the rebalancing:

root@debian01:/etc# gluster volume rebalance datastore status
rebalance step 1: layout fix in progress
root@debian01:/etc# gluster volume rebalance datastore status
rebalance step 1: layout fix in progress: fixed layout 41
root@debian01:/etc# gluster volume rebalance datastore status
rebalance step 1: layout fix in progress: fixed layout 69
root@debian01:/etc# gluster volume rebalance datastore status
rebalance step 2: data migration in progress: rebalanced 18 files of size 173669 (total files scanned 46)
root@debian01:/etc# gluster volume rebalance datastore status
rebalance step 2: data migration in progress: rebalanced 473 files of size 1634033 (total files scanned 1988)
root@debian01:/etc# gluster volume rebalance datastore status
rebalance completed: rebalanced 1121 files of size 3702686 (total files scanned 4977)

Accessing the Glusterfs volume with a client

If you mound the Glusterfs volume you specify only one of the storage server nodes,
but the client is using this node only to fetch the volume configuration. Subsequently,
the client will communicate directly will all available Glusterfs nodes.

mount the Glusterfs volume

Mount the Glusterfs volume datastore and fetch the configuration from debian01.

mkdir /mnt/datastore
root@slayer:~# mount -t glusterfs debian01:datastore /mnt/datastore

verify:

root@slayer:~# mount
/dev/sda1 on / type ext4 (rw,errors=remount-ro,commit=0)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/roger/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=roger)
/dev/sdb1 on /media/backup type vfat (rw,nosuid,nodev)
debian01:datastore on /mnt/datastore type fuse.glusterfs (rw,allow_other,default_permissions,max_read=131072)

Now I stopped the node debian01.

the Glusterfs volume is still available, although debian01 is disconnected:

root@slayer:~# ls -al /mnt/datastore/
insgesamt 2408
drwxr-xr-x  4 root root    8192 2012-04-17 17:25 .
drwxr-xr-x  6 root root    4096 2012-04-17 17:24 ..
-rw-r--r--  1 root root 2420250 2012-04-17 16:15 glusterfs.tar.gz
drwxr-xr-x  3 root root    8192 2012-04-17 17:17 usr
drwxr-xr-x 12 root root    8192 2012-04-17 17:25 virtualbox

root@debian02:/# gluster peer status
Number of Peers: 3

Hostname: debian01
Uuid: fc556a5f-4945-467b-b095-f874b90454f3
State: Peer in Cluster (Disconnected)

Hostname: debian04
Uuid: 65f37919-6f88-48fa-a782-b4292539a9bf
State: Peer in Cluster (Connected)

Hostname: debian03
Uuid: 380fda84-b952-4261-af55-27a9d8d1afbc
State: Peer in Cluster (Connected)

Logfiles

Find the logfiles of glusterfs:

root@debian01:/etc# gluster volume log locate datastore
log file location: /var/log/glusterfs/bricks
root@debian01:/etc# less /var/log/glusterfs/bricks/export-data.log

This tutorial is based on the gitorious – UbuntuInstallation tutorial.

In this setup I will use the hostname gitorious.linux-adm.de – change this hostname in your installation.

software installation

Required packages

apt-get install build-essential zlib1g-dev tcl-dev libexpat-dev \
    libcurl4-openssl-dev postfix apache2 mysql-server mysql-client \
    apg geoip-bin libgeoip1 libgeoip-dev sqlite3 libsqlite3-dev \
    imagemagick libpcre3 libpcre3-dev zlib1g zlib1g-dev libyaml-dev \
    libmysqlclient15-dev apache2-dev libonig-dev ruby-dev rubygems \
    libopenssl-ruby phpmyadmin libdbd-mysql-ruby libmysql-ruby \
    libmagick++-dev  zip unzip memcached git-core git-svn git-doc \
    git-cvs irb libxslt1.1 libxslt1-dev

Ruby, sphinxsearch, stompserver

apt-get install libchronic-ruby librmagick-ruby libdaemons-ruby \
ruby-hoe ruby-echoe libyadis-ruby ruby-mime-types libopenid-ruby \
libdifflcs-ruby libjson-ruby librack-ruby libhmac-ruby rake stompserver \
libapache2-mod-passenger rails sphinxsearch sphinxbase-utils

fetch gitorious

git clone git://gitorious.org/gitorious/mainline.git /var/www/gitorious

install missing ruby gems

cd /var/www/gitorious/
gem install bundler
bundle install

git user

Create a git user with the homedir in /var/www/gitorious/ and set the correct ownership.

adduser --system --home /var/www/gitorious/ --no-create-home --group --shell /bin/bash git
chown git:git -R /var/www/gitorious/

Create a directory for the repositories and a cache directory. Gitorious will add the SSH public keys of the registered users to the authorized_keys file, therefore we have to create a .ssh file and an empty authorized_keys file with the correct permissions.

su - git
git submodule init && \
git submodule update
mkdir -p tmp/pids
mkdir repositories
mkdir tarballs
mkdir .ssh
touch .ssh/authorized_keys
chmod 700 .ssh/
chmod 600 .ssh/authorized_keys

Put gitorious binary on path:

cat >> /var/www/gitorious/.bash_profile <<EOF
export PATH="$PATH:/var/www/gitorious/script/"
EOF

gitorious configuration

prepare configuration files

cd /var/www/gitorious
cp config/database.sample.yml config/database.yml
cp config/gitorious.sample.yml config/gitorious.yml
cp config/broker.yml.example config/broker.yml

create a secret key

Create a secret key for the session cookie. (we need this key later in the next step.

apg -m 32

setup config/gitorious.yml

Setup gitorious in /var/www/gitorious/config/gitorious.yml:


repository_base_path: "/var/www/gitorious/repositories"

is_gitorious_dot_org: false


Create the logroate configuration and the init scripts.

cp /var/www/gitorious/doc/templates/ubuntu/gitorious-logrotate /etc/logrotate.d/

cp /var/www/gitorious/doc/templates/ubuntu/git-ultrasphinx /etc/init.d/
cp /var/www/gitorious/doc/templates/ubuntu/git-daemon /etc/init.d/
cp /var/www/gitorious/doc/templates/ubuntu/git-poller /etc/init.d/

Set in /etc/init.d/git-daemon and in /etc/init.d/git-poller the RUBY_HOME variable to “/usr”

#RUBY_HOME="/opt/ruby-enterprise"
RUBY_HOME="/usr"


Activate the new gitorious init scripts

update-rc.d git-daemon defaults && \
    update-rc.d git-poller defaults && \
    update-rc.d git-ultrasphinx defaults

fix gem spec files

Try to start /etc/init.d/git-ultrasphinx
If you get the following error message you have to fix the spec files:

root@ubuntu03:/var/www/gitorious# /etc/init.d/git-ultrasphinx start
Invalid gemspec in [/var/lib/gems/1.8/specifications/json-1.5.4.gemspec]: invalid date format in specification: "2011-08-31 00:00:00.000000000Z"
Invalid gemspec in [/var/lib/gems/1.8/specifications/childprocess-0.2.1.gemspec]: invalid date format in specification: "2011-08-11 00:00:00.000000000Z"
Invalid gemspec in [/var/lib/gems/1.8/specifications/paperclip-2.4.5.gemspec]: invalid date format in specification: "2011-10-21 00:00:00.000000000Z"
(in /var/www/gitorious)
Invalid gemspec in [/var/lib/gems/1.8/specifications/json-1.5.4.gemspec]: invalid date format in specification: "2011-08-31 00:00:00.000000000Z"
Invalid gemspec in [/var/lib/gems/1.8/specifications/childprocess-0.2.1.gemspec]: invalid date format in specification: "2011-08-11 00:00:00.000000000Z"
Invalid gemspec in [/var/lib/gems/1.8/specifications/paperclip-2.4.5.gemspec]: invalid date format in specification: "2011-10-21 00:00:00.000000000Z"
Invalid gemspec in [/var/lib/gems/1.8/specifications/json-1.5.4.gemspec]: invalid date format in specification: "2011-08-31 00:00:00.000000000Z"
Invalid gemspec in [/var/lib/gems/1.8/specifications/childprocess-0.2.1.gemspec]: invalid date format in specification: "2011-08-11 00:00:00.000000000Z"
Invalid gemspec in [/var/lib/gems/1.8/specifications/paperclip-2.4.5.gemspec]: invalid date format in specification: "2011-10-21 00:00:00.000000000Z"
rake aborted!
Bundler couldn't find some gems. Did you run `bundle install`?
/var/www/gitorious/Rakefile:4
(See full trace by running task with --trace)

Change the “s.date” in the following spec files:

/var/lib/gems/1.8/specifications/json-1.5.4.gemspec
/var/lib/gems/1.8/specifications/childprocess-0.2.1.gemspec
/var/lib/gems/1.8/specifications/paperclip-2.4.5.gemspec

from:

s.date = %q{2011-08-31 00:00:00.000000000Z}

in:

s.date = %q{2012-08-31}


fix git-ultrasphinx

You have to fix the /var/www/gitorious/config/boot.rb file,
if you get the following error message after starting /etc/init.d/git-ultrasphinx.

root@ubuntu03:/var/www/gitorious# /etc/init.d/git-ultrasphinx start
(in /var/www/gitorious)
rake aborted!
uninitialized constant ActiveSupport::Dependencies::Mutex
/var/www/gitorious/Rakefile:10:in `require'
(See full trace by running task with --trace)

Add the following line in /var/www/gitorious/config/boot.rb.


# Don't change this file!
# Configure your app in config/environment.rb and config/environments/*.rb

require 'thread'


Apache configuration

Disable the default vhost configuration

a2dissite default
a2dissite default-ssl

create a new vhost configuration

cat >> /etc/apache2/sites-available/gitorious <<EOF
<VirtualHost *:80>
    ServerName gitorious.linux-adm.de         # change the hostname!
    DocumentRoot /var/www/gitorious/public
</VirtualHost>
EOF

create a new SSL vhost configuration

cat >> /etc/apache2/sites-available/gitorious-ssl <<EOF
<IfModule mod_ssl.c>
    <VirtualHost _default_:443>
        ServerName gitorious.linux-adm.de   # change the hostname!
        DocumentRoot /var/www/gitorious/public
        SSLEngine on
        SSLCertificateFile    /etc/ssl/certs/ssl-cert-snakeoil.pem
        SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key
        BrowserMatch ".*MSIE.*" nokeepalive ssl-unclean-shutdown downgrade-1.0 force-response-1.0
    </VirtualHost>
</IfModule>
EOF

a2ensite gitorious
a2ensite gitorious-ssl
a2enmod ssl   # enable SSL

create MySQL User for gitorious

mysql -u root -p
GRANT ALL PRIVILEGES ON *.* TO 'gitorious'@'localhost' IDENTIFIED BY 'XXXX' WITH GRANT OPTION;
FLUSH PRIVILEGES;

change the password XXXX!

Add the MySQL User to the production section in /var/www/gitorious/config/database.yml


production:
adapter: mysql
database: gitorious_production
username: gitorious
password: XXXX # change the password!
host: localhost
encoding: utf8


Starting gitorious

Run the following commands as user git.

export RAILS_ENV=production && 
bundle exec rake db:create && 
bundle exec rake db:migrate && 
bundle exec rake ultrasphinx:bootstrap

fix ultrasphinx/production.conf

If you get the following error message, you have to fix the /var/www/gitorious/ultrasphinx/production.conf file.

export RAILS_ENV=production && 
bundle exec rake db:create && 
bundle exec rake db:migrate && 
bundle exec rake ultrasphinx:bootstrap

Sphinx 0.9.9-release (r2117)
Copyright (c) 2001-2009, Andrew Aksyonoff

using config file '/var/www/gitorious/config/ultrasphinx/production.conf'...
WARNING: key 'address' is deprecated in /var/www/gitorious/config/ultrasphinx/production.conf line 11; use 'listen' instead.
listening on all interfaces, port=3312
WARNING: index 'main': preload: failed to open /var/www/gitorious/db/sphinx//sphinx_index_main.sph: No such file or directory; NOT SERVING
FATAL: no valid indexes to serve
Failed to start
Done
Please restart your application containers

Change in /var/www/gitorious/config/ultrasphinx/production.conf the word “base_tags” to “tags”.

git-ultrasphinx cronjob

Add the following cronjob for the git user.

crontab -e -u git


* * * * * cd /var/www/gitorious && /usr/local/bin/bundle exec rake ultrasphinx:index RAILS_ENV=production


create an admin user

git@ubuntu03:/var/www/gitorious$ env RAILS_ENV=production ruby1.8 script/create_admin
Type in Administrator's e-mail: 
admin@gitorious.linux-adm.de
Type in Administrator's password: 
test
Admin user created successfully.

screenshot

After a reboot of your system the gitorious web front-end should be available.

Usage: ./check_juniper_srx_ipsec_tunnel.pl -H <Juniper Hostname> -g <IPSec Tunnel Gateway> -C <SNMP Community>

You will find the plugin on my projects page

Cos the format for start_time of the ps command may change if the process was not started in the same year, I decided to take the neccessary informations from the /proc/<PID>/stat file.

In this file the process start time since boot is defined at the twenty-second field, expressed in Jiffies – the scale unit of the system timer. (One Jiffie is one tick of the system timer).

To convert Jiffies to seconds I just have to divide the number of Jiffies by the frequency (hertz) of the system timer, which is defined in the Linux Kernel header file include/asm-generic/param.h. The frequency may differ between Linux kernel versions and hardware platform! On my Linux systems the frequency is 100 HZ.

In a shell script the following line will determine the start-time of a process since boot time.

HZ="100"
((p_seconds_since_boot = $(cat /proc/$PID/stat | cut -d " " -f 22) / $HZ ))

To get the absolute start time I am adding the boot time of the Linux system from the /proc/stat file to the start time of
the process.

boottime=$(grep btime /proc/stat | cut -d " " -f 2)
(( p_starttime = $boottime + $p_seconds_since_boot ))

To get the runtime in seconds of the process I just subtract the absolute start time of the process from the actual time.

now=$(date "+%s")
(( p_runtime = $now - $p_starttime ))

Download the nagios / icinga plugin from my projects page or the check the following example which shows a simple shell script that takes a process string and determine the runtime and the start time.

#!/bin/bash
#------------------------------------------------------------
# starttime.sh
#------------------------------------------------------------


if (($# != 2)); then
        echo -e "\n\tUsage: $0 -p \"process string\" \n" >&2
        exit 4
fi

while getopts ":p:" opt; do
  case $opt in
    p)
                process="$OPTARG"
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      ;;
     :)
      echo "Option -$OPTARG requires an argument." >&2
      exit 1
      ;;
  esac
done

PID=$(pgrep -oxf "$process")
test -z $PID && {
        echo -e "\n\tError: \"$process\" not found\n\n"
        exit 4
}

test -f /proc/stat || {
        echo -e "\n\tError: \"/proc/stat\" not found\n\n"
        exit 4
}

HZ="100" 
now=$(date "+%s")

boottime=$(grep btime /proc/stat | cut -d " " -f 2)

((p_seconds_since_boot = $(cat /proc/$PID/stat | cut -d " " -f 22) / $HZ ))

(( p_starttime = $boottime + $p_seconds_since_boot ))

(( p_runtime = $now - $p_starttime ))

echo -en "\nProcess \"$process\" is running since "
echo -e "$p_runtime Seconds (Started: $(date -d @$p_starttime))\n"
#------------------------------------------------------------
# eof
#------------------------------------------------------------

Output of the script for the pidgin process.

roger@slayer:~/scripts/starttime$ ./starttime.sh -p pidgin

Process "pidgin" is running since 13795 Seconds (Started: Sa 31. Mär 14:28:13 CEST 2012)

Purpose

This document describes how to setup and configure bonding on debian linux.

General

Linux bonding is an arrangement of two or more network interfaces on the same host for redundancy or performance benefit. The new logical network interface is called bonding interface (devices are bond0, bond1, bond2,..) The network interfaces ethX becoming the slave interfaces. On other platforms bonding its known under different names, like port trunking on cisco IOS.

List of references

• Linux Hochverfügbarkeit: Einsatzszenarien und Praxislösungen (Galileo Computing)
• bonding.txt

Prerequisite

For this tutorial we need a linux debian host with at least two network interfaces (eth0, eth1).

Installation and setup

Install the following debian package.

apt-get install ifenslave-2.6

Bonding kernel module options

option mode

There are several bonding policies (mode)

• 0 = balance-rr. The default mode balance-rr is a round-robin policy providing load balancing and fault tolerance, use this mode for performance benefits.
• 1 = active-backup. In the active-backup mode, only one slave of the bond is active, if a link failure is detected on it, another slave becomes active and takes over the MAC address of the last active slave.
• 2 = balance-xor. This mode is using all slaves, and the link for the transmisson, is calculated by the following policy [(source MAC address XOR'd with destination MAC address)modulo slave count], to select other. This mode is configurable with the xmit_hash_policy. This modes provides load balancing and fault tolerance
• 3 = broadcast. Broadcast from all slaves. This mode provides fault tolerance
• 4 = 802.3ad. IEEE 802.3ad Dynamic link aggregation. A switch thats supports IEEE 802.3ad Dynamic link aggregation is needed
• 5 = balance-tlb. In this mode, the incoming traffic is received by the active slave, the outgoing traffic is load balanced through all slaves, depending on the current slaves load.

For the complete description read the official documentation: bonding.txt In this tutorial we will use mode 1 (active-backup)

To change the mode of an active bonding device use the sysfs interface

echo 1 > /sys/class/net/bond0/bonding/mode

option miimon

The option miimon defines how often the MII link is monitored (in milliseconds). We will use a value of 100 for our setup.

option max_bonds

max_bonds defines the number of bonding devices the kernel module has to create. (Default is 1)

option downdelay

Downdelay defines the time to wait before deactivating a slave, after a link failure has been detected. We will use a value of 200 for our setup.

option updelay

Updelay defines the time to wait before activating a slave, after a link recovery has been detected. We will use a value of 200 for our setup

Setup bonding manually

modprobe bonding mode=1 miimon=100 max_bonds=1 downdelay=200 updelay=200

load module at system startup

Add the following lines to /etc/modprobe.d/arch/x86_64 or /etc/modprobe.d/arch/i386, depending on your systems architecture.

alias bond0 bonding
options bonding mode=1 miimon=100 downdelay=200 updelay=200

Add the following line to /etc/modules to load the bonding module at the system startup.

bonding

Update kernel modules

update-modules

Start the bonding interface manually

Start the bonding interface with the ifconfig command (Replace IP, NETMASK and BROADCAST with the correct values for your network before)

ifconfig bond0 IP netmask NETMASK broadcast BROADCAST up

Attach the network interfaces eth0 and eth1 to the bond0 interface with the ifenslave command

ifenslave bond0 eth0
ifenslave bond0 eth1

The bonding interface is now available, use one of the next /etc/network/interface configurations, to start the bonding interface automatically at system startup.

setup the interface

Add the following lines to /etc/network/interfaces and replace IP, NETMASK, GATEWAY and BROADCAST with the correct values for your network.

auto bond0
iface bond0 inet static
address IP
netmask NETMASK
up /sbin/ifenslave bond0 eth0
up /sbin/ifenslave bond0 eth1
gateway GATEWAY
broadcast BROADCAST

restart networking

Restart your network configuration with the following command

/etc/init.d/networking restart

Setup the bonding interface automatically

Add the following lines to /etc/network/interfaces and replace IP, NETMASK, GATEWAY and BROADCAST with the correct values for your network.

In this setup, the mode of the bonding modul is configured in the interfaces file. It`s not necessary to define the mode of the bonding interface at the module load time in this setup. Other supported options are bond_mode, bond_miimon, bond_primary, bond_updelay, bond_downdelay, bond_arp_ip_target, bond_arp_interval, bond_xmit_hash_policy and bond_lacp_rate.

setup the interface

Add the following lines to /etc/network/interfaces

iface bond0 inet static
address IP
netmask NETMASK
broadcast BROADCAST
gateway GATEWAY
slaves eth0 eth1
bond_mode active-backup
bond_primary eth0

restart networking

Restart your network configuration with the following command

/etc/init.d/networking restart

status monitoring

The status of the bonding interface is in /proc/net/bonding/bond0

user@host:~ # cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.5.0 (November 4, 2008)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: eth1
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 200
Down Delay (ms): 200

Slave Interface: eth0
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:28:18:47:11:2e
Slave Interface: eth1
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:28:18:47:11:2f

Example cronjob from /etc/crontab or the crontab -e command:

*/2 * * * * /usr/local/bin/apache_check.pl /var/log/apache2/error.log || /etc/init.d/apache2 restart

#!/usr/bin/perl -w
#------------------------------------------------------------
# save position
#------------------------------------------------------------
sub save_pos {
my $pos = $_[0];
my $file = $_[1];

open(POS, ">$file") || die "error";
     print POS "$pos";
     close(POS);
}

#------------------------------------------------------------
# get position
#------------------------------------------------------------
sub get_pos {
     my $file = $_[0];
     my $pos = 0;

      open(POS, "<$file") || die "error";;

      $pos=(<POS>);
      if ($pos !~ /^\d+/) {
        $pos=0;
      }
      close(POS);
      return $pos;
}

#------------------------------------------------------------
# main
#------------------------------------------------------------
my $datafile="";

if (defined $ARGV[0] && -r $ARGV[0] ) {
       $datafile="$ARGV[0]";
} else {
       die "Usage: $0 \n";
}
my $posfile="/tmp/pos.txt";
my $oldpos=0;
my $lines=0;
my $foundpattern=0;
my $ret=0;

if (-e $datafile) {
       open(DATA, "<$datafile") || die "error";
       if (-e $posfile) {
              $oldpos=get_pos($posfile);
              # check if this is a new file
              seek(DATA, 0, 2);
              if ($oldpos > tell(DATA)) {
                            #print "new file - e.g. logrotate\n";
                            $oldpos=0;
              }
              seek(DATA, $oldpos, 0);
        }
        while(<DATA>) {
              $lines++;
              #print "$_";
              if ($_ =~ /child pid [d]+ exit signal Segmentation fault/) {
                            #print "Found pattern\n";
                            $foundpattern++;
              }
        }
        if ($lines > 0) {
              #print "Save Pos!n";
              save_pos(tell(DATA), $posfile);
        }
        close(DATA);
}

print "Found pattern $foundpattern times\n";
if ($foundpattern > 0) {
	$ret=1;
}

exit $ret;
#------------------------------------------------------------
# eof
#------------------------------------------------------------

nmon can display / capture the following performance data

• CPU utilization
• Memory use
• Kernel statistics and run queue
• Disks I/O rates, transfers, and read/write ratios
• File systems size and free space
• Disk adapters
• Network I/O rates, transfers, and read/write ratios
• Paging space and paging rates
• Machine details, CPU and OS specification
• Top processors
• User defined disk groups
• Asynchronous I/O – AIX only
• Workload Manager – AIX only
• ESS and other disk subsystem – AIX only
• Dynamic LPAR changes – AIX and Linux (on POWER hardware)

list of references

• http://nmon.sourceforge.net/pmwiki.php

Installation

Install nmon on Ubuntu / Debian with the following command

apt-get install nmon

using nmon

Run the nmon command with the -h option to get the help.

interactive mode

Run the nmon command as a normale user (root user is not necessary!) and select the performance information you want to display in the nmon tool with the following keys.

h = Online help information
r = Machine type, machine name, cache details and OS version + LPAR
c = CPU by processor stats with bar graphs
l = long term CPU (over 75 snapshots) with bar graphs
m = Memory stats
L = Huge memory page stats
V = Virtual Memory and Swap stats
k = Kernel Internal stats
n = Network stats and errors
N = NFS Network File System
d = Disk I/O Graphs
D = Disk I/O Stats
o = Disk I/O Map (one character per disk showing how busy it is)
o = User Defined Disk Groups
j = File Systems
t = Top Process stats use 1,3,4,5 to select the data & order
u = Top Process full command details
v = Verbose mode – tries to make recommendations
b = black and white mode (or use -b option)
. = minimum mode i.e. only busy disks and processes

key — Other Controls —
+ = double the screen refresh time
– = halves the screen refresh time
q = quit (also x, e or control-C)
0 = reset peak counts to zero (peak = “>”)
space = refresh screen now

capture mode

To capture the perfomance data into a comma separated file run the nmon command with the -f option (spreadsheet output format) and the -s (interval) and -c (number of refreshes) options.

In this example, nmon will capture the performance data every seconds and will exit after 30 refreshes.

nmon -f -s1 -c 30

nmun will run in the background like a daemon, and you can logout of the system while nmon is running.

The perfomance data will be written to a file with your hostname as prefix and the date and time (e.g.slayer_110928_2126.nmon)

The performance data for each refresh (called snapshot) is identified by a uniq tag. To get all tags from the capture file use the following grep command.

grep ZZZZ your_capture_file.nmon

for example:

roger@slayer:~$ grep ZZZZ slayer_110928_2126.nmon 
ZZZZ,T0001,21:26:07,28-SEP-2011
ZZZZ,T0002,21:26:08,28-SEP-2011
ZZZZ,T0003,21:26:09,28-SEP-2011
ZZZZ,T0004,21:26:10,28-SEP-2011
ZZZZ,T0005,21:26:11,28-SEP-2011
ZZZZ,T0006,21:26:12,28-SEP-2011
ZZZZ,T0007,21:26:13,28-SEP-2011
ZZZZ,T0008,21:26:14,28-SEP-2011
ZZZZ,T0009,21:26:15,28-SEP-2011
ZZZZ,T0010,21:26:16,28-SEP-2011
ZZZZ,T0011,21:26:17,28-SEP-2011
ZZZZ,T0012,21:26:18,28-SEP-2011
ZZZZ,T0013,21:26:19,28-SEP-2011
ZZZZ,T0014,21:26:20,28-SEP-2011
ZZZZ,T0015,21:26:21,28-SEP-2011
ZZZZ,T0016,21:26:22,28-SEP-2011
ZZZZ,T0017,21:26:23,28-SEP-2011
ZZZZ,T0018,21:26:24,28-SEP-2011
ZZZZ,T0019,21:26:25,28-SEP-2011
ZZZZ,T0020,21:26:26,28-SEP-2011
ZZZZ,T0021,21:26:27,28-SEP-2011
ZZZZ,T0022,21:26:28,28-SEP-2011
ZZZZ,T0023,21:26:29,28-SEP-2011
ZZZZ,T0024,21:26:30,28-SEP-2011
ZZZZ,T0025,21:26:31,28-SEP-2011
ZZZZ,T0026,21:26:32,28-SEP-2011
ZZZZ,T0027,21:26:33,28-SEP-2011
ZZZZ,T0028,21:26:34,28-SEP-2011
ZZZZ,T0029,21:26:35,28-SEP-2011
ZZZZ,T0030,21:26:36,28-SEP-2011

To get the performance data of a specified tag use the grep command again

roger@slayer:~$ grep T0019 slayer_110928_2126.nmon 
ZZZZ,T0019,21:26:25,28-SEP-2011
CPU01,T0019,3.0,0.0,0.0,97.0
CPU02,T0019,3.0,1.0,0.0,96.0
CPU03,T0019,0.0,0.0,0.0,100.0
CPU04,T0019,1.0,0.0,0.0,99.0
CPU_ALL,T0019,1.8,0.3,0.0,98.0,,4
MEM,T0019,3961.7,-0.0,-0.0,7629.4,1711.4,-0.0,-0.0,7629.3,-0.0,863.3,1209.7,-1.0,105.3,0.0,533.6
VM,T0019,-1,-1,-1,831,-1,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,76,76,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-7
PROC,T0019,1.0,-1.0,1599.3,-1.0,-1.0,-1.0,0.0,-1.0,-1.0,-1.0
NET,T0019,0.0,436.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
NETPACKET,T0019,0.0,326.2,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
JFSFILE,T0019,20.0,0.0,0.1,0.0,0.0,14.4
DISKBUSY,T0019,1.0,1.0,0.0,0.0,0.0
DISKREAD,T0019,0.0,0.0,0.0,0.0,0.0
DISKWRITE,T0019,75.8,75.8,0.0,0.0,0.0
DISKXFER,T0019,3.0,3.0,0.0,0.0,0.0
DISKBSIZE,T0019,25.3,25.3,0.0,0.0,0.0

purpose

This document describes how to set up a FAI install server 3.4.8 on Debian Linux 6.x with dhcpd3 or dnsmasq

list of references

• fai project

related article

• PXE network boot of grml rescue system
• Tutorial: booting SystemRescueCd with PXE/NFS
• http://thekelleys.org.uk/dnsmasq/doc.html
• http://www.isc.org/software/dhcp

prerequisite

software

The FAI install server is installed with a Debian Squeeze 6.x, and apt-cacher is installed.

Hardware

I will use the following network and hardware informations (MAC address), change these settings for your setup!

• FAI install server, Debian Squeeze 6.x, IP 192.168.2.245, Hostname fai.local
• Client debian-vm-01, MAC address 00:16:3e:1c:64:9b, IP: 192.168.2.240

install FAI

Add the FAI repository to a new configuration file named /etc/apt/sources.list.d/fai.list

deb http://fai-project.org/download squeeze koeln

To verify the packages from fai-project, add the following gpg key

c

gpg -a --recv-keys AB9B66FD; gpg -a --export AB9B66FD | apt-key add -

Now we install the FAI packages and some helper tools

apt-get install fai-server fai-client fai-doc fai-setup-storage fai-quickstart makepasswd dnsmasq

Answer all questions during the installation with the default answer.

setup FAI

FAI

fai logging user

During the installation, clients will send logfiles to the “fai” user.

useradd -d /home/fai -m -s /bin/bash -c "FAI logging" fai

/etc/fai/fai.conf

Open /etc/fai/fai.conf in your favourite editor and add/edit the following options.

FAI_CONFIG_SRC=nfs://192.168.2.245/srv/fai/config
LOGUSER=fai
FAI_DEBMIRROR=192.168.2.245:/srv/mirror/debian-squeeze
MNTPOINT=/media/mirror
FAI=/var/lib/fai/config

Use the makepasswd command, to create a new password, and add the encrypted password to the FAI_ROOTPW variable in the /etc/fai/make-fai-nfsroot.conf configuration file. (default password is fai)

user@host:/ # makepasswd --crypt-md5
e2TjmLPMW     $1$zu3UkGiA$ylbHHsa7WQ1VJm3d4YkQQ/

fai-setup

Run the fai-setup command to create the nfs root directory, NFS exports and to add the FAI user to the system.

fai-setup -v
cp -a /usr/share/doc/fai-doc/examples/simple/* /srv/fai/config/

NFS exports

Add the following NFS exports to /etc/exports and restart the NFS Kernel Daemon:

cat >> /etc/exports   << "EOF"
/srv/fai/config 192.168.2.0/255.255.255.0(async,ro,no_subtree_check)
/srv/fai/nfsroot 192.168.2.0/255.255.255.0(async,ro,no_subtree_check,no_root_squash) 
/srv/mirror/debian-squeeze 192.168.2.0/255.255.255.0(async,ro,no_subtree_check) 
EOF
/etc/init.d/nfs-kernel-server restart

FAI / Debian mirror

The fai-mirror script creates a mirror of the needed Debian packages (defined in /srv/fai/config/package_config/)

mkdir -p /srv/mirror/debian-squeeze
fai-mirror /srv/mirror/debian-squeeze/

NFS root

With the following command we will create the FAI nfsroot:

make-fai-nfsroot -v

Add to the nfsroot apt sources configuration (/srv/fai/nfsroot/live/filesystem.dir/etc/apt/sources.list) the apt-cacher proxy (including Debian backports repositories) – Check the releated articled for the apt-cacher setup.

deb http://192.168.2.44/apt-cacher/ftp.de.debian.org/debian/ squeeze main non-free contrib
deb http://192.168.2.44/apt-cacher/security.debian.org/ squeeze/updates main non-free contrib
deb http://192.168.2.44/apt-cacher/fai-project.org/download squeeze koeln

Set the boot NFS option in /srv/fai/nfsroot/live/filesystem.dir/etc/initramfs-tools/initramfs.conf to NFS

BOOT=nfs

setup PXE

pxelinux.cfg

# copy the menu binary
cp /usr/lib/syslinux/menu.c32 /srv/tftp/fai

cat > /srv/tftp/fai/pxelinux.cfg/default << "EOF"
DEFAULT menu.c32                                                                                                    # Prompt user for selection                                                                                                   PROMPT 0                                                                                                           

menu color tabmsg 37;40      #80ffffff #00000000
menu color hotsel 30;47      #40000000 #20ffffff
menu color sel 30;47      #40000000 #20ffffff
menu color scrollbar 30;47      #40000000 #20ffffff
MENU WIDTH 80
MENU MARGIN 10
MENU PASSWORDMARGIN 3
MENU ROWS 12
MENU TABMSGROW 18
MENU CMDLINEROW 18
MENU ENDROW 24
MENU PASSWORDROW 11
MENU TIMEOUTROW 20
TIMEOUT 100
ALLOWOPTIONS 1

MENU TITLE PXE Boot Menu

LABEL local
        menu label ^Boot local harddisk
        menu default
        localboot 0

LABEL install
menu label Debian Squeeze Install 
KERNEL vmlinuz-2.6.32-5-amd64
APPEND ip=dhcp boot=live netboot=nfs nfsroot=192.168.2.245:/srv/fai/nfsroot root=/dev/nfs initrd=initrd.img-2.6.32-5-amd64 FAI_FLAGS="createvt,sshd,verbose" FAI_ACTION=install panic=60
EOF

tftpd

Setup the tftpd-hpa daemon in /etc/default/tftpd-hpa to serve the kernel and initrd file to the install client.

TFTP_USERNAME=”tftp”
TFTP_DIRECTORY=”/srv/tftp/fai”
TFTP_ADDRESS=”0.0.0.0:69″
TFTP_OPTIONS=”–secure”

DHCP/bootp

Decide, if you want to use dnsmasq, or dhcpd3

dnsmasq

cp /etc/dnsmasq.conf /etc/dnsmasq.conf.backup
cat > /etc/dnsmasq.conf  << "EOF"
dhcp-range=192.168.2.235,192.168.2.240,static
dhcp-host=00:16:3e:1c:64:9b,debian-vm-03
dhcp-boot=pxelinux.0
log-queries
log-dhcp

dhcp

cp /etc/dhcp/dhcpd.conf /etc/dhcp/dhcpd.conf.backup
cat > /etc/dhcp/dhcpd.conf  << "EOF"
log-facility local7;
 
option dhcp-max-message-size 2048;
use-host-decl-names on;
deny unknown-clients;
 
allow bootp;
allow booting;
 
option domain-name "local";
option domain-name-servers 192.168.2.245;
 
 
subnet 192.168.2.0 netmask 255.255.255.0 {
  option routers 192.168.2.1;
  option broadcast-address 192.168.2.255;
}
 
group {
 
        filename "pxelinux.0";
        next-server 192.168.2.245;
 
        option root-path "192.168.2.245:/srv/fai/nfsroot";
 
        host test1 {
                hardware ethernet 00:16:3e:1c:64:9b;
                fixed-address 192.168.2.240;
        }
}
 
EOF

Install the client

Boot the client with PXE boot enabled (enable PXE in the Clients BIOS) and select “Debian Squeeze Install” from the menu.

list of references

For a complete list of available commands for the used protocols check the RFCs please:

• RFC – Post Office Protocol – Version 3
• RFC – Simple Mail Transfer Protocol
• RFC – INTERNET MESSAGE ACCESS PROTOCOL – VERSION 4rev1
• RFC – Hypertext Transfer Protocol — HTTP/1.1

SMTP

sending mail

In the first example I will open a telnet connection to a SMTP Server on localhost port 25 and send an email to a local email address.

Replace example.net with the domain of your SMTP server, and use an existing user in the email address.

user@host:~# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 mail.example.net ESMTP
helo testing
250 mail.example.net 
mail from: user@example.net 
250 2.1.0 Ok
rcpt to: local@example.net
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>

from: user@example.net
to: local@example.net
Subject: test 1908
 

Test 1908

.
250 2.0.0 Ok: queued as 2BA152A005D
quit
221 2.0.0 Bye
Connection closed by foreign host.

SMTP STARTTLS (SSL)

An encrypted SMTP connection can`t be handled by telnet, so I will use the openssl s_client command.

check StartTLS support

To check if your SMTP server supports the StartTLS command, open a telnet connection and use the ehlo command to get a list of supported commands.

user@host:~# telnet localhost 25
220 mail.example.net ESMTP
ehlo testing
250-mail.example.net
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
quit

encrypted SMTP (SSL) connection

If your SMTP server supports the StartTLS command, run the following command, to open an encrpyted SMTP connection to 127.0.0.1 on port 25.

user@host:~#  openssl s_client -starttls smtp -crlf -connect 127.0.0.1:25
<output of the certificate verification .. >
---

250 DSN
ehlo testing
250-mail.example.net
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
mail from: user@example.net
250 2.1.0 Ok
rcpt to: local@example.net
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>
From: user@example.net
To: local@example.net
Subject: test 1908

Test 1908

.
250 2.0.0 Ok: queued as 12C842A005D
quit

POP3

POP3 plain

Login to the POP3 server with a telnet connection on localhost port 110.

username: local@example.net
password: JZY+0t6dF$278%

user@host:~#  telnet localhost 110
Trying 0.0.0.0...
Connected to 0.
Escape character is '^]'.
+OK Hello there.
user local@example.net
+OK Password required.
pass JZY+0t6dF$278%
+OK logged in.
stat
+OK 47 13458471
quit

POP3 SSL

Use the openssl s_client command to open an encrypted connection to localhost port 995.

username: local@example.net
password: JZY+0t6dF$278%

user@host:~#  openssl s_client -connect 127.0.0.1:995
Trying 0.0.0.0...
Connected to 0.
Escape character is '^]'.
+OK Hello there.
user local@example.net
+OK Password required.
pass JZY+0t6dF$278%
+OK logged in.
stat
+OK 47 13458471
quit

SMTP AUTH

In my example, I will use the following user and password to authenticate against the SMTP server with SMTP AUTH

username: local
password: JZY+0t6dF$278%

For the SMTP AUTH, we need an base64 encoded string of the username and the password.
Use the following perl command, to get the authentication string:

user@host:~# perl -MMIME::Base64 -e 'print encode_base64(" 00local 00JZY+0t6dF$278%")'
AGxvY2FsAEpaWSswdDZkRiU=

Open again an encrypted SMTP connection, and use the AUTH PLAIN command with the generated base64 string of the username and password.

user@host:~# openssl s_client -starttls smtp -crlf -connect 127.0.0.1:25
ehlo testing
250-mail.example.net
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
AUTH PLAIN AGxvY2FsAEpaWSswdDZkRiU=
235 2.7.0 Authentication successful

If the authentication fails, you will get an error message:

535 5.7.8 Error: authentication failed: bad protocol / cancel

IMAP

IMAP SSL / IMAPs

To test the IMAP connection, I will use the openssl s_client command, the following user account and the 1 LOGIN username password command.

username: local
password: JZY+0t6dF$278%

user@host:~# openssl s_client -connect 127.0.0.1:993
<output of the certificate verification .. >
---

* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE AUTH=PLAIN AUTH=LOGIN] Dovecot ready.
1 LOGIN local JZY+0t6dF$278%
1 OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT IDLE CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS] Logged in

Select a mailbox with the SELECT command to get access to the messages in the mailbox.

1 select inbox
* FLAGS (Answered Flagged Deleted Seen Draft)
* OK [PERMANENTFLAGS (Answered Flagged Deleted Seen Draft *)] Flags       ted.
* 3214 EXISTS
* 0 RECENT
* OK [UNSEEN 4] First unseen.
* OK [UIDVALIDITY 1311685071] UIDs valid
* OK [UIDNEXT 3215] Predicted next UID
* OK [HIGHESTMODSEQ 6] Highest
1 OK [READ-WRITE] Select completed.

To fetch the header of a message in the mailbox use the fetch command:

1 fetch 1 all
* 1 FETCH (FLAGS (Seen) INTERNALDATE "25-Jul-2011 19:41:03 +0200" RFC822.SIZE 923 ENVELOPE ("Mon, 25 Jul 2011 19:40:58 +0200 (CEST)" "test1" ((NIL NIL "local" "example.net")) ((NIL NIL "local" "example.net")) ((NIL NIL "local" "example.net")) ((NIL NIL "undisclosed-recipients" NIL)(NIL NIL NIL NIL)) NIL NIL NIL "<20110725124058.A900F2A004C@mail.example.net>"))
1 OK Fetch completed.

To fetch the mail with the header and the body use the following command:

1 fetch 1 body[]
* 1 FETCH (BODY[] {923}
Return-Path: <user@example.net>
X-Original-To: local@example.net
Delivered-To: local@example.net
Received: from mail.example.net (localhost [127.0.0.1])
       by mail.example.net (Postfix) with ESMTP id A900F2A004C
       for <local@example.net>; Mon, 25 Jul 2011 19:40:58 +0200 (CEST)
       by mail.example.net (Postfix) with SMTP
       for <local@example.net>; Mon, 25 Jul 2011 19:40:57 +0200 (CEST)
from: user@example.net
Subject: test 1922
Message-Id: <20110725124058.A900F2A004C@mail.example.net>
Date: Mon, 25 Jul 2011 19:40:58 +0200 (CEST)
To: undisclosed-recipients:;


test

)
1 OK Fetch completed.

HTTP

unencrypted HTTP

Open a telnet connection to a remote host on port 80 and get the file /test.html from the web server.
Enter return twice after you typed the following command:

GET /test.html HTTP/1.1
HOST: www.linux-adm.de

user@host:~# telnet www.linux-adm.de 80
Trying 46.163.114.237...
Connected to www.linux-adm.de.
Escape character is '^]'.

GET /index.html HTTP/1.1
HOST: www.linux-adm.de

 

HTTP/1.1 200 OK
Date: Fri, 02 Sep 2011 18:22:46 GMT
Server: Apache/2.2.14 (Ubuntu)
Last-Modified: Wed, 17 Aug 2011 18:40:01 GMT
ETag: "10c8ca17-745-4aab7d2e80240"
Accept-Ranges: bytes
Content-Length: 1861
Vary: Accept-Encoding
Content-Type: text/html

encrypted HTTP

Open a SSL connection a remote host on port 443 with the openssl s_client command and get the file /test.html from the web server.
Enter return twice after you typed the following command:

GET /test.html HTTP/1.1
HOST: ssl.linux-adm.de

openssl s_client -connect ssl.linux-adm.de:443
<output of the certificate verification .. >
---

GET /test.html HTTP/1.1
HOST: ssl.linux-adm.de

HTTP/1.1 200 OK
Date: Fri, 02 Sep 2011 18:24:48 GMT
Server: Apache/2.2.14 (Ubuntu)
Last-Modified: Fri, 02 Sep 2011 18:24:36 GMT
ETag: "15dac002-e-4abf9793ba100"
Accept-Ranges: bytes
Content-Length: 14
Vary: Accept-Encoding
Content-Type: text/html
X-Pad: avoid browser bug

<h1>test</h1>