Wednesday, August 02, 2006

Switch over

So why did clustering not work? We [two of us] tried everything we could for a week to get clustering to work. Sadly we couldn't make it work with the resources we had. Reading what other people were doing online with clustering I found that most people had 30 Gig RAM or more in their servers [we have 1 Gig in ours and many home machines have half that].

To get that amount of RAM you need four 8 Gig RAM cards. Each 8 Gig RAM card costs approx 11,000 US dollars... yes, you do did read that right, so to have 32 Gig in two servers would cost just under 90,000 US dollars, that's just under 50,000 pounds sterling! So, assuming the price would drop within the lifetime of the servers we investigated... only to find our servers would only take 4 Gig RAM and to get more powerful motherboards would cost another silly amount of money... so forget that.

So we then spent two more days rebuilding the system to be a 'replication pair' of servers. This is not as powerful as a cluster but works well with the resources we have available. And we have now switched over to the new system.

Alongside this, the video editing project needed a new DVD authoring program - that's the software that enables menus and other clever things to be added to DVDs. The new software refused to work properly, producing very jittery images. I tried all things to make it right and nothing seemed to work. So... reluctantly I phoned technical support in the USA. This is a charge service so I was trying to do every option before incurring extra costs.

Tech support was not very helpful. Having asked all the options about what I had tried they then suggested that the display adaptor software on the computer was out of date [we had the latest software] or maybe the DVD burner needed new firmware [we had the latest firmware] or maybe the DVDs themselves were bad [we have used them successfully for months] - everything but a problem with their software of course. Not helpful.

This morning I woke up thinking maybe there was a problem with the GOP structure of the files. Oh, yuk this is really technical! GOP stands for the highly technical phrase 'Group of Pictures' and what happens on a DVD is that every so often they have a complete picture but within the 'group of pictures' they only have the differences between the pictures. This saves a huge amount of disk space. Hmmm... but... the GOP structures were correct.

I then read somewhere online that somehad had a problem with the 'field dominance order' of some video capture cards... I wonder??? 'Field Dominance Order' really is too technical to explain simply. But basically normal TV has the top field first but DV tapes have the lower field first. OK, strangely... very strangely... very strangely indeed... it appears that if I invert the field dominance order in the program making the video files and then invert it again [ie put it back where it started] in the program making the DVD it works! But... the quality is not quite what is needed as I had to convert the file to Quicktime and back again. So... more investigation.

Third breakthrough... Peter had been struggling with some computers in our 'lab' which were refusing to work. They are regular desktop computers, but he found today that if he turned off the battery saving system [normally only of use on laptops] they work correctly. As the Americans say 'Go figure'.

So we move on... this is really boring but necessary stuff.

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