Re: No 2 gig limit for /cdrom/KNOPPIX/KNOPPIX in Knoppix 5.0.1?
Hi Klaus!
> CAUTION: The "2 Gig limit" is NOT a cloop or linuxrc limit! cloop
> supports 64 bit pointers, and therefore VERY large files (in todays
> dimensions). The limit is within the root iso9660 filesystem: iso9660
> only supports FILES smaller than 2GB. Really. Even that you CAN create
> an iso9660 image with mkisofs that contains files larger than 2GB, the
> filesystem itself will kind of "wrap around" at 2GB, and read invalid
> data from every file above the limit.
Thank you for you information.
K3b uses growisofs over 2 gig because mkisofs can't handle so large files
and can exceed 2 gig limit safely. Am I right?
> At first glance, you won't notice, because the "table of contents" is in
> the first blocks of the file system. But every time you access files (or
> blocks) above the 2GB limit of the KNOPPIX/KNOPPIX file, the iso
> filesystem will return just WRONG data to you.
Hope you are wrong ;)
> I noticed this problem first on the 4.0 DVD image. Everything works
> fine, unless you try to list the packages with dpkg -l, then dpkg
> reports that it cannot read the dpkg database (which is, you guessed it,
> because it's above the 2GB limit).
No problem with 'dpkg -l' here. Everything is listed right.
> Now, you could circumvent this by not using iso as your base file system
> where those compressed images are stored (for example, by using udf).
> But this makes the DVD incompatible with older operating systems. An
> ext2 file system just won't boot because you cannot place a el torito
> boot record on it.
Time to forget ext2 and use ext3 or reiserfs? There is, of course, old
computers that don't even accept isolinux (only syslinux) but usually they
don't even have DVD drive. So I have forget myself old computers. But real
Knoppix (not a remastered one) is something more and needs to be more
compatible with older machines, too. I see.
>> Simple changing 'test -f' to 'test -r' everywhere in linuxrc makes it!
> I already replaced these for version 5.0, for a different reason, but it
> does not do anything for the file system limit. of iso9660.
I have many minirt.gz files for testing purposes and one time my system
couldn't find KNOPPIX image because it was little over 2 gig by size. But
boooting from linuxrc from Knoppix 5.0 (I got it somewhere) could boot!
Then I looked with kdiff3 what is the difference and noticed that 'test
-r' thing. Changing only 'test -f' to 'test -r' in my linuxrc make KNOPPIX
accessible also from my minirt.gx! No more modifications.
> You were just lucky, because the remaining 700MB of the uncmpressed
> files were not used yet. Do a md5sum check on all files, and you will
> see. ;-)
Just doing in the background and seen nothing yet ;)
I have also made a new remastering from my 'too big' DVD with Fabian
Franz's menu based scripts and no error even when copying files. I have
included that remaster script in my remastering. Hope you are wrong
because remastering with those menu based scripts don't work with two
compressed KNOPPIX files. Could those scripts be modified to use more than
one KNOPPIX file to help remasterings?
Just writing from my 'too big' remastered DVD...
-tapsa-
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