Archive for September, 2006

Installing VMware Server 1.0.1 on Centos 4.4

Thursday, September 21st, 2006

This is not very complicated, apart from one libgcc-issue that was fatal and kept me busy for a couple of hours.

If the correct version of libgcc_s is not found then VMware Server will not run correctly. For me it crashed every time I tried to create a virtual machine.

You can either link to the libgcc_s.so which accompanies the VMware Server distribution

ln -s /usr/lib/vmware/lib/libgcc_s.so.1/libgcc_s.so.1 /lib/libgcc_s.so.1

or install the compatibility library

yum install compat-libstdc++-33

Installing Dell OpenManage 5.1 (OMSA) on Centos 4.4 (and PowerEdge 1850)

Wednesday, September 20th, 2006

- Install SNMP agent (important to do this before installing OMSA)
yum install net-snmp net-snmp-utils

- Ensure necessary packages are installed
yum install ncurses libxml2 compat-libstdc++-33

- Download OMSA Managed Node from Dell, unpack and edit setup.sh to use the “RHEL4″ by default, since Centos is not a known operating system to the script. Then run setup.sh.

Choose “4″ and then “i” to install all packages. Install to default locations.

After installation run “srvadmin-services.sh start”

Sometimes it is necessary to start ipmi separately
srvadmin-services.sh stop
/etc/init.d/ipmi start
srvadmin-services.sh start

- Now it should be possible to “walk” the Dell MIB

snmpwalk -v 2c -c public 127.0.0.1 enterprises.674.10892

It should also be possible to open a browser and point it to
https://server:1311 (where server is your servername) in order
to access the OpenManage web interface.

Installing Centos 4.4 on Dell PowerEdge 1850

Wednesday, September 20th, 2006

We have four Dell PowerEdge 1850 servers with 2 x 3.0 GHz CPU, 2 x 73 GB SCSI HD (in RAID-1 configuration) and 4 GB RAM on which we now run CentOS 4.4. I think hese are great servers, easy to install and reliable.

My favorite method for installing Centos 4.4 (and I have done it numerous times, trust me) is to download only iso 1 (out of 4), burn it and boot from it. There is noting specific to the PowerEdge servers in these first steps but then we want Dell OpenManage in order to be able to monitor the server in full. We currently use Nagios and SNMP to monitor our environment.

During the installation I choose “Custom” and then de-select all packages. The installation process will only need the first cd for this and I can then “yum install” the packages needed afterwards. I also include the firewall (even though we also have a hardware appliance in front of our servers) and activate SE Linux.

Post-installation:

  • Remove “en_US.UTF-8″ from /etc/sysconfig/i18n
  • “yum update”
  • Install kernel source for being able to compile modules later on
    yum -y install kernel-devel
  • Install NTP and sync the clock for correct time
    yum -y install ntp
    ntpdate ntp.lth.se
  • Install VIM enhanced since only minimal is installed during the minimal install
    yum -y install vim-enhanced
  • Install MySQL 5 from CentosPlus
    yum -y –enablerepo=centosplus install mysql-server-5.0.22
  • Update Perl CPAN
    perl -MCPAN -e shell
    install Bundle::CPAN
  • Install SNMP agent and Dell OpenManage (see separate article)

FileCentral

Wednesday, September 6th, 2006

FileCentral.se provides an easy way to send large files (too large to send by e-mail), similar to YouSendIt. It is a free service hosted on a 100 Mbps fiber connection and you can see your history of sent files as well as receive e-mail notifications when a recipient downloads the file. Check it out!

PAM, OTP and SMS

Tuesday, September 5th, 2006

I have just started writing a PAM module for authentication using One Time Passwords (OTP) sent to the user’s mobile phone via SMS.

The idea is adding a PAM module to the stack for sshd (or other services) with the following functionality:

  • First use “normal” authentication of type “requisite”. That is if the normal username/password combination is not entered correctly by the user, the user is rejected.
  • Check if the user originates from an IP address configured as trusted. If yes, approve authentication without further action.
  • For non-trusted IP addresses check if the user is configured in the “OTP database” and if yes, generate an OTP and send to the user’s mobile phone.
  • The user is prompted for the OTP and if entered correctly authectication is approved. For incorrect password start the authentication process all over again.

The PAM module will send the password using a HTTP POST on the format used by our own SMS Submit service. However, letting the URL be configurable the module can be configured to use any SMS service that can use the parameters sent.

First objective is to make it run in Linux, but then it would be nice to be able to support other operating systems as well.