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Re: maximum LUN [message #63922]

Mon, 24 November 2008 08:00

greg.addr
Messages: 160
Registered: May 2007

Senior Member

> What reason could there possibly be for having hundreds
> of files open simultaneously? The only thing that comes
> immediately to mind for me is a poor programming concept. :-)

I kind of expected that reply... :) I think I do have a valid
application, though. I have an archive of a few thousand satellite
images, each of which has 6 bands, stored in separate files. I've made
an object which can handle the six bands and return a subset image for
a selected region processed as I want it. It also returns the image's
coverage of the region, so that I can fill in any gaps with data from
other images. This I do by opening further image objects. So far, I
can use four of these to make an on-the-fly mosaic before I run out of
LUNs - and it works well up to that point. The program allows zooming
and panning, so I need repeat access to similar regions of the same
files. I think it would be too slow to close and reopen them every
time, so the objects hold the files open. The archive is several
terabytes, changing, and not in my control - so preprocessing is out.
With 128 LUNs instead of 28 I could mosaic about 20 image subsets,
which will be enough for the moment. Still, if the number 128 was just
an arbitrary choice long ago, I'd like to ask early for a bigger one!

cheers,
Greg

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[Message index]

		Re: maximum LUN By: greg.addr on Mon, 24 November 2008 08:00
		Re: maximum LUN By: David Fanning on Mon, 24 November 2008 06:51
		Re: maximum LUN By: R.Bauer on Mon, 24 November 2008 10:30
		Re: maximum LUN By: Vince Hradil on Mon, 24 November 2008 09:19

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