Gisteren en vandaag vond (en vindt) in de British Library voor de vijfde keer iPRES (international Conference on Preservation of Digital Objects) plaats. En het mooie van deze tijden is dat van de lezingen bijna live een verslag te volgen is. Zie bijvoorbeeld de bijdragen van Chris Rusbridge op de Digital Curation Blog.Ik pik er nu even een paar interessante citaten uit.
Over kosten en risico's
Richard Wright talking about storage and the “cost of risk”. In early days dropping a storage device meant losing a few kilobytes, now it could be GBytes and years of work. Storage costs declining and capacity increasing exponentially roughly related to Moore’s law (doubling every 18 months). Usage is going up, too, and risk is proportionate to usage, so risk is going up too. Risk proportional to no of devices and to size and to use… plus the more commonly discussed format obsolescence, IT infrastructure obsolescence etc. So if storage gets really cheap, it gets really risky!
Reports work from Manfred Thaller of Koln: one bad byte affects only that byte of a TIFF (does this depend on selected compression?), 2% of a JPEG, and 17% of a JPEG2000. Demonstrated 5 errors on a PNG and a BMP: former illegible, latter has a few dots scattered about. Text files the best: one byte corruption affects only that byte! (...) Can’t emphasise how important this is: one of the most worrying preconceptions in digital preservation is that the bit preservation element is a solved problem. It isn’t!
Over emulatie
I’ve always had a problem with emulation; perhaps I’ve too long a memory of those early days of MS-DOS, when emulators were quite good at running well-behaved programs, but were rubbish at many common programs, which broke the rule-book and went straight into the interrupt vectors to get performance. OK, if you’re not that old, maybe emulation does work better these days, and is even getting trendy under the new name of virtualisation. My other problem is also a virtue of emulation: you will be presented with the object’s “original” interface, or look and feel. This sounds good, but in practice the world has moved on and most people don’t like old interfaces, even if historians may want them. I guess emulation can work well for objects which are “viewed”, in some sense; it’s not clear to me that one can easily interwork an emulated object with a current object.
Vooral die laatste twee opmerkingen vind ik interessant en moet ik nog eens over nadenken.
En tenslotte een presentatie van Brian Kelly over website-archivering. (Toevallig is dat nu heel actueel in mijn eigen organisatie, vandaar mijn belangstelling).
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