danei Posted March 30, 2009 Posted March 30, 2009 The original files are about 1.0GB and occupying about 1.2GB, but after optimized about 20MB space there is still a 1.6GB iso file. I can't figure out why from the point of sector size or something I knew. So I get log attatched behind. img.log
LIGHTNING UK! Posted March 30, 2009 Posted March 30, 2009 Because you've got a HUGE number of files and therefore a lot of slack space (zeroes at the end of a file to pad out the sector), not to mention all the file system descriptors that need to be present (at least 1 sector each) in order to represent those files.
danei Posted March 30, 2009 Author Posted March 30, 2009 Because you've got a HUGE number of files and therefore a lot of slack space (zeroes at the end of a file to pad out the sector), not to mention all the file system descriptors that need to be present (at least 1 sector each) in order to represent those files. Oh, I did a little calculation just than. the pading space is not as big as it seems, which is less than 100MB. But the file index's really huge which takes all the extra space left, That's about 500MB. Maybe the disc file system could be designed to reduce this by something like a file alloc table.
LIGHTNING UK! Posted March 30, 2009 Posted March 30, 2009 I don't design the file systems, I simply follow the specs (as best I can!). Blame the ISO9660, Joliet, UDF guys for that. Your disc would be smaller if you didn't use UDF at all. And I assume you know that only Vista (and newer) machines can read UDF 2.60 by default yeah? Windows XP (and earlier) require a 3rd party driver to read anything over 1.50 (or perhaps 2.01?).
mmalves Posted March 30, 2009 Posted March 30, 2009 http://en.wikipedia.org/wiki/Universal_Dis...tive_OS_support
danei Posted March 30, 2009 Author Posted March 30, 2009 I don't design the file systems, I simply follow the specs (as best I can!). Blame the ISO9660, Joliet, UDF guys for that. Your disc would be smaller if you didn't use UDF at all. And I assume you know that only Vista (and newer) machines can read UDF 2.60 by default yeah? Windows XP (and earlier) require a 3rd party driver to read anything over 1.50 (or perhaps 2.01?). Oh, I meant nothing blaming you, not at all. Fs thing is due to the people who design it. I know that only vista can handle udf 2.6, which is blueray disc spec. I make the iso only to bakup something and I won't publish to anyone else so I won't consider other system. So udf uses more file index/descriptor space than iso9660?
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