LinkedIn helpfully tells everyone it is 99 days since I wrote a blog post. Thanks LinkedIn. A few non-IT projects have been in progress (and summer holidays as well).
On the IT side, I have recently managed to download ESXi5.0 and install it easily on a USB stick. I’ve imported guests from my datastore and got the appliance based virtual center running. All very easy, I am happy to report!
Touching on IT, I have built a VM and installed Magento e-commerce web shopping software for a related project.
For a client, I have written a few simple load generating scripts in perl to help testing a virtual environment. It’s not as easy as you think to generate memory load. Just assigning a large chunk of RAM doesn’t work as the host operating system (Linux in this case) notices the memory is not being accessed and pages it out over time. You can see it happening in a nice graph in virtualcenter. ESXi will probably try to do something clever too, even if the O/S doesn’t. To keep RAM in use, you need to continuously access it, which I did with random accesses into an array.
I made it along to the September OpenSolaris User Group meeting where Nick Todd gave a talk on the Solaris linker and Alastair Lumsden gave an update on the OpenIndiana project (which I am downloading now).
Nick’s talk was entitled “The Missing Link”. Apt, as we all tend to take that step for granted but there’s a decent amount of engineering in there. It was interesting to note that even in the days of card decks, you nearly always had to “bracket” your deck with pre- and post- instructions to tell the machine what to do with your deck. That concept lives on in the elf file format where executable code is prefixed by crt1 and crtn code.
There are two main aspects of linking: the link editor and the runtime linker and a set of Solaris commands to aid development and debugging, not least of which is “elfdump”.
This talk was fascinating, not least because it simply reminded us that this goes on and contained plently of tips and places for further reading. (I will insert links when I get them).
Alastair gave an update on OpenIndiana (1 year old!) and the upcoming 151a stable release. OpenIndiana is based on Solaris 11 express and Illumos but future releases will fork from Oracle and enable innovation and new features. KVM has been added and GCC will be used as a compiler. The combination of these various technologies: KVM, Qemu, Illumos, ZFS, Crossbow, Zones, Dtrace is a potent mix.
Not least the consideration that the source code is freely available and if you are serious about security there is no substitute for examining and compiling the code yourself. Particularly with recent hacks against the Linux kernel.