AiHua Information Technology Site

I’ve had some interest in Moodle as a Learning Management System (LMS) lately. Here’s a quick guide to setting up Moodle on your own Ubuntu 8.04 LTS server:

1. Install Ubuntu Server 8.04
2. #: sudo apt-get update
3. #: sudo apt-get dist-upgrade
4. #: sudo apt-get install mysql-server php5-mysql apache2 libapache2-mod-security php5-ldap php5-odbc libapache2-mod-php5 php5-gd openssh-server phpmyadmin unzip zip aspell-en curl libcurl3 libcurl3-dev php5-curl php5-xmlrpc clamav-base clamav-freshclam clamav
5. #: sudo /etc/init.d/apache2 restart
6. #: cd /var/www
7. #: sudo wget http://download.moodle.org/stable19/moodle-latest-19.tgz
8. #: sudo tar -zxf moodle-latest-19.tgz
9. #: sudo mkdir /var/moodledata
10. #: sudo chown -R www-data.www-data /var/moodledata/
11. #: sudo /etc/init.d/apache2 restart
12. Point a browser to http://(yourubuntuhostipaddress)/phpmyadmin and create a database for moodle. Something like “moodle” for a database name. It’s easiest to create a user called moodle and select the option to create a matching database. The new user should have full rights and privileges
for the moodle database.
13. #: Point a browser to http://(yourubuntuhostipaddress)/moodle and follow the install instructions
14. At this point you should have a fully functioning moodle install, congratulations!

While it is possible to omit some of the packages, these packages represent a solid antiviral system for the assignments that get uploaded as well as provide extended feature support for Moodle.

If you are still having trouble, contact us via the “contact us” page on the right.

There is no denying that it is highly beneficial to have centralized authentication and file services.  Over the years we have made a lot of strides in AiHua.  Our first server was an old box with Mepis on it that served as our file server during the spring of 2006.  Our next few systems were based on LTSP or DRBL which effectively both have centralized login’s and centralized file repositories.  It makes a huge difference when staff can login to their own desktop and files from any computer in the building.  It also allows for them to continue working at another station or with a computer/thin client that is in reserve.

When an entire company is comprised of linux/unix desktops and servers, it’s easy to set up LDAP services for authentication and NFS for centralized storage; however, windows computers are not so simple.  In the past it took some level of expertise in both unix/linux and windows machines to create an effective ldap/samba replacement for a domain controller, it isn’t overly daunting and there is a great deal of information on the internet; however, it’s still not for the faint of heart.

This is where a fantastic open source project called ebox comes in.  Ebox installs ontop of ubuntu (a free/open source linux) server editions and provides an out of the box domain controller!  It also features easy to use web interfaces to add users, groups, and computers.  It’s no one trick pony, as it also features a firewall/gateway, proxy/nat, DHCP, TFTP, jabber server, e-mail server, and VPN server out of the box.

We recommend you give it a try and replace the Windows servers around your office with this powerful solution.  If you need help setting it up or setting up a PDC on another linux distribution like openSuse, we are availible.  Follow the links to the right to contact us.

Sometimes we just don’t want to allow every staff to use every program, there are easy ways to deal with this in Ubuntu.  One of my favorites is to assign programs to groups.  For example if we want to restrict who can use skype and pidgin within Ubuntu we can create a group called “im” for instant messenger.  I prefer to do this in LDAP as I can do it for the entire organization in one go, but you can create the group for the individual computer using the users and groups tool.  Next I do the following:

cd /usr/bin
sudo chown root:im skype pidgin
sudo chmod o-rx skype pidgin

This will make the above programs only accessible to root and user placed within the im group.  The sky is the limit as to how you want to authorize personnel to utilize their company resources,  but this approach will completely block access to the types of programs you don’t want company wide access to, such as accounting software (even if there is password protection for the financial database, the only people that should be able to execute the financial software should be authorized personnel).

We hope this article has been informative and helpful, as always you can enquire for use of our services through the contacts page on the right.

It seems that in the virtualization race that a couple of relatively new entrants are making headway.  The first, proxmox, works much like a hypervisor for xen.  It actually runs on a modified Debian linux, making it quite similar to one of our favorite distributions in the office: Ubuntu linux, which is also based on Debian.  It’s a true open source project that also supports openvz guests which have a speed advantage but are restricted in which operating systems can be virtualized.

The second new development comes from Sun Microsystems who is soon going to offer an open sourced virtualization server which is also based on xen.  This one will be a hypervisor based on OpenSolaris (which is a tried and true unix variant and makes our list of favorites with Ubuntu and OpenSuse) and thus features some of the fantastic features that Solaris variants have.  The most exciting of which is native support for the most advanced file system available: ZFS.  It will also feature interoperability with their acquired technology from VirtualBox (an open source product I heartily recommend to desktop users who need or want virtualization) and has a vastly improved interface compared to previous interface attempts by Sun Microsystems.

These technologies will make implementation and installation much quicker and significantly simpler for organizations to achieve.  It will also make deployment of virtualized appliances (such as those offered by AiHua) easily installed by persons with minimal technical know how (as configuration can be primarily achieved by IT personnel prior to distribution).  They also seem to support many more hardware configurations than the often expensive name brand servers that ESXi seems to prefer.

To discuss the feasibility and potential benefits and side effects you can use the contact page to engage our consultation services.

I’m often asked why I (Isaac) choose to implement PXE booting at the AiHua offices.  For those unfamiliar with the concept of PXE booting, it is a technology which allows computer administrators to remove the hard drives of all their client machines and only need to manage the software/operating system that exists at the server.

This affords a couple of advantages, first software changes do not need to be repeated for every computer on the network.  Second, the client hardware becomes expendable, a computer which dies due to hardware fault is quickly replaced by another computer, the employee only notices that the computer case changed.  All files and settings remain unchanged.  All files and folders are located centrally, making sharing and backup a trivial task.  Finally, there is significant cost saving as IT staff require less time maintaining and recovering individual computers, leading to less staff to salary and less overtime hours.

There are some dissadvantages to consider as well, primarily in the consideration that another point of failure has been included.  If the server has broken down, then no computers are able to perform their work.  This risk is minimized by regular backup schedules and the use of high availability services (typically a group of servers and storage arrays).

How would I recommed the small to medium sized organization implement their network?  If the organization has less than 5 computers then I would suggest using standard technologies; however, if more than 10 computers then diskless booting begins to have an effect.  By the time their are 50 to 200 computers diskless begins to really shine (particularly with a 1 Gig network and network attached storage solution).

AiHua can provide expertise in setting up diskless networks.  We presently have experience with building custom diskless, LTSP, freeNX, and DRBL.  Each has advantages and dissadvantages that we can help you navigate through and pick what would be best for your organization, if any is viable at all for your situation.  See the contact page for details.

We nearly hit the six months worth of non interupted uptime mark for a DRBL server that was built for one of the Bless China International locations.  This means that until today when a day long power outage unfortunately forced me to shut it down before the battery gave up, there has been no downtime for six months!  There were 5 departments using the server everyday, all day long to boot from, access their files, and access the internet.

This sort of reliability speaks volumes about the quality of open source software and it’s practicality for office use.  The calls for service during the past few months were few and far between and primarily consisted of questions about how to make a spreadsheet row longer or how to change text background colors.  I’m saddened that I didn’t get to see how long it would hold out for, but I believe all those uptime calculations about Unix and Linux that are put out every year now!

I was excited to see that VMware has made their ESXi hypervisor free for installation.  We have been using virtualization technologies for years around the AiHua offices mainly for development work (mostly virtualbox and VMware Server/Player), and recently we have conglomerated our servers onto a single VMware Server 2.0 installation atop a headless Ubuntu 8.04 Server installation.  From there we can host all the individual servers and appliances we need.  It has greatly increased the ease at which we administer our networks.

ESXi will further improve performance and reliability because there is no need to install an underlying server from which VMware Server would need to run.  It also allows setting up extra ethernet cards and iscsi targets in the event of hardware failures.  The only downside is that the VI Client to manage the hypervisor itself is currently Windows only; however, there is a linux version on the horizon which bodes well for organizations looking to free themselves of licensing costs.

The best feature of virtualization comes in the ability to hand over ready made tools to organizations.  Servers can very much become drop in components!  At AiHua Consulting we have even managed to load a few virtual machines onto a VMware server and instantly have a network with pxe boot capabilities, ldap, thin clients, or even NAS/SAN/iscsi.  If the need arises, these parts can be later substituded for real steel hardware (I still like to have a nice RAID array for a storage solution, but in a pinch it’s nice to know I can drop one in as an appliance until I have the bits and pieces for a storage server).

To learn more about how virtualization can help your organization please use the contact us page.

Here’s a quick tip I ran across regarding the use of financial software.  There are lots of free financial products available for linux, particularly if you are involved in sales or manufacturing.  However, it’s much more difficult if you are an NGO and need a funds accounting solution.

I discovered that it’s very possible to handle a single project by using any of the free software as follows: 1.) Donors are Customers! 2.) sales are the donations and are one method from which you can send donor reports later. 3.) You can use product codes to denote how funds were spent as well.

I’m not an accountant, but using a donor<->customer frame of thinking will handle fund accounting for a single project (that uses a single ledger).  Beyond a single project you need software that allows for multiple ledgers and is intentionally made for fund accounting (be warned these can be very costly).

Good luck, if you are in need of assistance with accounting or selecting software for your accounting needs feel free to contact us via the contacts page to set up a consultation.