A week of interesting technology

Last week I had the opportunity to use a number of interesting technologies and applications. I've already blogged about the Cisco Network Assistant, but that was only the beginning.

We were running a VMware Server virtual machine that was not performing correctly. The physical hardware was not up to the job, so we wanted to migrate the VM to our ESX server. The VM was configured to use a virtual IDE disk which prevented us from importing it directly into ESX. Enter VMware Converter. This piece of software allowed us to step through a wizard where we selected the source VM files, and then entered the server name we wanted to save the machine. A few other options later (selecting the destination datastore and similar), and the conversion process started. Twenty five minutes later it was all done. The converted VM had been streamed into place and was ready to go. Really simple and worked first time. I was impressed!

The end of the week gave me the opportunity to experiment with Sun Logical Domains (LDOMs). This hypervisor based VM technology can be found on the Coolthreads range (using the new sun4v architecture). Unlike Containers, LDOMs allow different Solaris versions to be installed. We're testing the performance of the machine to run as an Ingres server, so I'll most probably update the blog later this week with more information.

This week looks equally promising - Apple's WWDC was yesterday, although I haven't watched the keynote yet. The 3G iPhone isn't unexpected, but is now quite tempting, even with a £35/month contract as I can't think of a better mobile web browsing device. And then there is the announcement of "MobileMe" (aka, "Exchange for the rest of us"). It's certainly something to look into to...

A day with Cisco Network Assistant

Today I spent a significant amount of time using the freely available Cisco Network Assistant. This tool allows you to probe your [Cisco] LAN and identify the topology. This proved very useful as although I had a rough idea of how the network was wired, the software highlighted a couple of issues that I need to resolve. Once identified, you can directly interact with the devices, renaming switches, creating VLANs, enabling and disabling ports. Really, really nice - especially for the price.

The reason I'm doing this is that I want to get the topology accurately mapped before starting my Nagios deployment for network monitoring.

The only downside was discovering the SFP modules we bought for server interlinking were not "Cisco Compatible", so we'll have to spend double to get the same thing!

Sun Certified System Administrator

Today I took the Sun Certified System Administrator for the Solaris 10 Operating System Upgrade Exam (snappy title huh?). I passed - but only just.

To aid me in my revision, I used the "Sun Certified System Administrator for Solaris 10 Study Guide" by Paul Sanghera published by Osborne, and "Exam Prep Solaris 10 System Administration" by Bill Calkins published by Que. This is on top of using Solaris on a daily basis for the last eight years.

After revising from both these books and taking the test questions, I was consistently getting over 80% from both books. Considering the passmark is 60% for the upgrade, it looked pretty good.

So imagine my surprise when I sat down in the exam and was confronted by a number of questions that are not covered in either book! The confidentiality agreement prevents me from detailing too much about the content, but I was also surprised to find that the questions were based on a small subset of topics.

This is apparently because Sun have upgraded the exams earlier this year and the books are not yet updated. Calkins has a update on his website detailing the changes (which I've only just found!).

So beware if you want to revise this certification! It's not a walk in the park and make sure you know your Flash from your Grub...!

Wireless EEE problems

Although I've used the EEE PC on a number of different wireless networks, I could not get it to connect to my Netgear DG834G at home. It would see the network, but would not connect and obtain a DHCP address.

To cut a *very* long story short, the problem was that I had configured access lists on the router so that only specified MAC addresses could connect. This was denying the EEE PC access before it even got as far as authenticating.

I added the EEE to the list of allowed addresses and a minute later was happily connected to the web using WPA encrypted wireless.

Nice.

8bit nostalgia

Over the last few days I've been browsing sites dedicated to the old 8bit BBC micro made by Acorn computers in the 1980s. I was first exposed to the BBC at primary school where I think they had two of them (for the entire school!). When I reached secondary school, I joined the break and lunchtime "Computer Club".

At home we had an Acorn Electron. This was a cut down version of the BBC that ran at a slower speed (1Mhz vs 2Mhz), only a single channel for sound and missed the memory efficient Mode 7 screen mode. This did not deter me from adding a printer, disc drive and some ROM cartridges (for word processing and spreadsheets). My Dad then used the machine to write up notes and sermons.

At school I used the Acorn Archimedes (the first RISC computer available to the masses) but for home use I eventually got a 286 PC and he upgraded to a BBC Master - the pinnacle of BBC 8bit computing.

This would have been in about 1993. So why blog about it now?

I'm realising in my browsing just how well designed the BBC was. No other machine had the potential for expansion or the fantastic BBC BASIC. The implementation of BASIC was beyond all other 8bit micros and had named procedures and an inbuilt assembler. The operating system (16k!) provided access to the hardware in a very simple way.

The BBC could have benefited from some better graphics (say 16 colours at a 320x256?) and a beefed up sound chip (it's not bad, but not as powerful as the SID in the C64), but it remains to this day a classic machine that can stand proudly among its peers.

I must visit my parents and hunt down the BBC Master...

VMware Server Performance Issue

I've been running VMware Server on the SilverShuttle for a while now (140 days and counting!). The little machine is generally running very well with its two VMs - Solaris Nevada and CentOS, but occasionally the machine stutters very badly and the load average within the virtual machines shoot up from the 0.1 they usually are to about 40.0!

Unfortunately, running top and prstat did little to suggest any reason, and the host operating system (SUSE 10.1) didn't seem to be having any problems of its own apart from the VMware processes which were now taking a lot more CPU.

Cutting to the conclusion, after a period of investigating what might be the cause, I turned off the powersaved daemon on the host operating system. Since then, performance has been rosy. I'm guessing the powersaving was kicking it, misreporting the CPU speed to the VMs which were then choking (but it's just a theory).

All is now well.

Installing Alfresco

A week ago I decided to install the Alfresco open source enterprise content management system on my CentOS VM. The basic install is very easy, comprising of creating /opt/alfresco and untarring the downloaded file into it. The demo version uses HSQL as a content repository, but this isn't recommended for production use.

I opted to change the datasource to MySQL and after setting up the database (using the script provided), I had problems starting the Alfresco installation. I then ran out of time and abandoned it.

Today I went back to the install and after doing some reading up, found that the problem was due to changing the content repository from HSQL to MySQL. As I had no content to worry about, I deleted /opt/alfresco and reinstalled. The big difference this time being that I did not start the installation before I changed the settings to MySQL.

And it works! I now need to learn how to use it, but it appears to be a very powerful piece of software. More blogging soon...