Tuesday, June 14, 2011

Fedora 15 makes /media a tmpfs

The /media directory is defined in the Filesystem Hierarchy Standard as containing subdirectories "which are used as mount points for removeable media such as floppy disks, cdroms and zip disks".

Some people, myself included, have been known to use this location to mount more semi-permanent media such as additional hard drives or even network shares below this location. I fully recognise that this was always folly of me, but hey - for a long time it worked.

As of Fedora 15 the /media directory has become a tmpfs by default. This means that among other things it is wiped on reboot. Any devices still plugged in will of course be detected when the system starts and their mounts will re-appear in the directory.

What this means for those of us who have been abusing this area of the filesystem is that our mounts have 'disappeared' since the first reboot after the upgrade.

Simply issuing umount /media as root is enough to temporarily return your mounts to their previous state so that you can move the data to a less controversial location.

Wednesday, June 8, 2011

An Introduction to Amazon Web Services, Post-presentation Reflections.

Today I was lucky enough to attend a presentation given by Simone Brunozzi (@simon) who works for Amazon Web Services (AWS). The slides from the presentation are available on slideshare but I thought I would take the time to quickly reflect on a few key points that I took away from it.

Who needs Venture Capital?

The biggest thing I took away from today was that AWS presents an amazing opportunity for small startups to get off the ground without necessarily needing to acquire large amounts of venture capital. Even when venture capital is being sought the value proposition is much more attractive to potential sources of funding than a traditional proposal. Using AWS the funding required can scale appropriately along with the success (or failure) of the venture itself rather than requiring a large outlay up front.

Indistinguishable Experience for End Users

While the list of large, well known, companies using AWS to support their web presence is quite long how many of their users realize the services they use are backed by it? For the most part, ignoring the recent well publicized outage, the user experience of a correctly defined AWS setup is completely indistinguishable to end users from that of a traditionally hosted site. In some instances it may even be better thanks to the use of services like CloudFront!

Everyone has a Unique or Unsolvable Problem

Based on the under currents of some of the questions posed in today's session it seems that many in IT, at least locally here in Australia, still believe that their organisation is somehow unique. Indeed in many cases this may in some small way be true. The problem is that this line of thinking is the precursor to the argument that an organisation's problems cannot possibly be solved by generically designed platform or framework of the day X.

This isn't an attitude unique to today's attendees by any means, and I don't particularly hold it against them either. There are obvious risks attached to a change in platform mix for any established organisation. That said I couldn't help but wonder, given the previous point regarding how invisible AWS is from an end user experience perspective, how many of these same organisations already have competitors leveraging the efficiencies of the cloud and they aren't even aware of it.

Security of Platform

A common thread of concern in the Question and Answer session was what I will refer to as security of platform. That is to ask the question "what is to stop AWS yanking my site at will". The answer unfortunately appears to be "trust us, we wont - it's not in our interests". The only real test of this that has come to light was with regards to WikiLeaks and in that particular case the site was indeed taken off AWS.

Amazon argue that the reason WikiLeaks was removed from AWS was in fact due to the fact that they were clearly not the owners of the content they were serving and thus violated the Terms of Service. Whether or not this is the case it seems that business users are still very much concerned about the ramifications of building their IT infrastructure on top of a platform that can, at least technically, be pulled out from under them at a moments notice.

Along a similar line there is concern that currently there is no Australian region for almost any services provided by AWS. As a result jurisdiction over data stored by Australian companies using these services ultimately resides with foreign governments. For many organizations this is simply unpalatable and often in fact impossible due to legislative requirements.

Unfortunately given Australia's small population and the small number of regions currently available in AWS it seems unlikely that this will be changing any time soon.