Showing posts from 2013

PPTP server on AWS Ubuntu instance

Simple VPN server configuration for easy VPN access to AWS using built in Windows VPN client.
First to install pptp server package. sudo apt-get install pptpd
Now to configuration:
edit /etc/pptpd.conf
option /etc/ppp/pptpd-options logwtmp localip  remoteip
edit  /etc/ppp/pptpd-options
refuse-pap refuse-chap refuse-mschap require-mschap-v2 require-mppe-128 ms-dns ms-dns proxyarp nodefaultroute lock nobsdcomp

fixing missing apt-add-repository command

You might need to use apt-add-repository script and will get a missing command error. For example:
sudo: apt-add-repository: command not found

in order to fix that you nred to install  python-software-properties package # apt-get install python-software-properties

That's it.

Provided by:Forthscale systems, cloud experts

How to disable network manager Red Hat 6 based distributions (RHEL, CentOS, Oracle Linux)

To stop Network Manger ( for example then using pacemaker cluster) execute as root:
service NetworkManager stop
To prevent Network Manager Service from starting at boot execute as root:
# chkconfig NetworkManager off

Keep in mind that you now need to manually configure your network interfaces.

Provided by:Forthscale systems, cloud experts

How to turn off SELINUX in Red - Hat based distributions including CentOS, Oracle Linux and Fedora?

To check  if SELinux is running execute following command:
# getenforce

To disable it, execute the following command:
# setenforce Permissive

This will put selinux in a passive (allow all) mode and last until the machine is rebooted.
 To permanently disable it, change SELINUX= line in: /etc/sysconfig/selinux.

Provided by:Forthscale systems, cloud experts

working and tested USB install procedure for RH 6 based distributions (RHEL 6.x, CentOS 6.x, Oracle Linux 6.x and others)

We needed to install CentOS 6.4 machines with USB and got into absolute madness. All RHEL cones have no working procedure and workarounds consisted of using FAT32 partition with 3rd party tools (problematic with install ISO files greater than 4GB) or multiple partitions and remounts. Until we found a very simple solution that did not work as well and fixed it.

To create the USB You will need:
Red hat based distribution to create the USB (in our case CentOS-6.4-x86_64-bin-DVD1.iso). Actual CD iso image Fedora livecd-iso-to-disk scriptSteps are very simple:
Insert the USB stick to the port.
You need to find out the device name (for ex. /dev/sdb1 )
On systems with auto-mount just run df -h or plug it in and run dmesg | tail -20

Install livecd tools:
yum install livecd-tools

Make sure it is bootable  (for ex. /dev/sdb1, via editing it`s parent - sdb ):
/sbin/parted /dev/sdb
(parted) toggle 1 boot
(parted) quit

Format it with ext3 (does not support ext4)
mkfs.ext3 /dev/sdb1

Prepare the USB (for ex…

Accessing NoMachine NX Server as root

IN a default installation on NX server root access is disabled. To allow root login just follow those simple steps.

Edit file:

and substitute line reading

#EnableAdministratorLogin = "0" 
EnableAdministratorLogin = "1"
save the file and exit.

and run in shell as a root user:

/usr/NX/bin/nxserver --useradd root

this is it. Changes will take affect immediately.

Setting up updates with public yum server for Oracle Enterprise Linux

Oracle provides a free and public yum server to update it`s Enterprise Linux distribution.
It is easy to set-up and it supports versions 4, 5 and 6.

To set up public repositories for different versions, download configuration file (for ex. with wget)
In Oracle Enterprise Linux 6.x# cd /etc/yum.repos.d # wget In Oracle Enterprise Linux 5.x# cd /etc/yum.repos.d # wget In Oracle Enterprise Linux 4, Update 6 or Newer# cd /etc/yum.repos.d# if you have old repo file then: # mv Oracle-Base.repo Oracle-Base.repo.disabled # wget
You can verify new configuration with:
#  yum list

And execute update with :
# yum update

Provided by: Forthscale systems, scalable infrastructure experts

Vertica installation tutorial

How to install Vertica Analytic DatabaseDownload VerticaDownload Vertica RPM from the site For this tutorial we are using Community Edition 6.1.2-0, which is the latest version so far. This version has bug, that need to fixed manually in multiple nodes install, the bug will be fixed in next versions.
Server preparationBefore installing Vertica few things must be done on the server and some of the are optional(but strongly suggested). All this steps must be done on all nodes if installing multi node solution.        
Must configurationsInstall Linux OS - we are using Centos 6.4 for this tutorial Check that the server is has at least 1 GB RAM free(minimum for install, we suggest     to have more memory for normal usage) [root@vertica01 ~]# free -m             total       used       free     shared    buffers     cached Mem:          1877        465       1412          0         14        343 -/+ buffers/cache:        106       1770 Swap:         3039          0       3039 …

How to install PGPool II on PostgreSQL Servers in master-slave architecture + PGPoolAdmin web managment

General InformationPGPool can run on same server along with PostgreSQL DB or on stand alone server(recommended). In this article we will install PGPool on stand alone server, but the only difference is connection ports on PGPool and PostgreSQL. We will install PGPool II 3.1 on PostgreSQL 9.1.

Basic architecture: ┏───────────────┓ │                │ │    pgpool-1    │ │  pgpool server │ │                │ ┗───────────────┛ //             \\ //               \\ //                 \\ \\//                \\// \/                  \/ ┏───────────────┓           ┏───────────────┓ │                │           │                │ │    pgsql-1     │ streaming │     pgsql-2    │ │  pgsql master  │══════════>│  pgsql slave   │ │     server     │replication│     server     │ │                │           │                │ ┗───────────────┛           ┗───────────────┛

Fail cases:Slave failsIn case slave server will fail PGPool will start script and will mark server as Down (state 3). I…