Re: [MiNT] Max file size

[Peter Slegg <p.slegg@scubadivers.co.uk>]

On Fri, 20 Aug 2010 14:17:50 -0400, "Roger Burrows" <rfburrows@ymail.com> wrote:
> Hi Peter,
> On 20 Aug 2010 at 14:33, Peter Slegg wrote:
>
> > I have had this question answered before but no amount of googling
> > finds the reply.
> >
> > http://www.google.co.uk/search?hl=en&ie=ISO%2D8859%2D1&q=site%3Asparemint%2Eat
> > ariforge%2Enet+partition
> >
> > What is the max file size on Mint partitions ?
> >
> > I have just upgraded to CD Writer Suite (DVD) and surprised to find that
> > the maximum it can write to DVD is limited to 2 GByte by the os. The ext2
> > docs suggest this could be bigger.
> >
> > http://en.wikipedia.org/wiki/Ext2
> >
> As noted by many others earlier today, 2GB is the limit for the underlying
> Fwrite() system call (and associated file access calls).  Windows had the same
> problem and initially pushed it to 4GB-1 with a kludge, the major one being
> that the equivalent of Fseek() returned -1L on any error; other apparently
> negative long values returned were to be treated as unsigned positive file
> positions.  This of course was only useful for new/updated apps.
>
> Sizes greater than 4GB require a new set of system calls, which is a fairly big
> job (and again obviously would only be useful for new/updated apps).  If such
> support does appear in MiNT, we'll update CD Writer Suite to use it!
>
> As someone suggested, CDISO could support a .ISO file larger than 2GB without
> changes to the operating system by splitting it into multiple subfiles.  We'll
> consider it for an enhancement; yours is the first (indirect) request for this
> feature, probably because most users don't have an Ext2 filesystem handy.
>
> Roger
>

Hi Roger,

I hadn't given any thought to this issue until I tried to write a bundle of
files to DVD. Luckily the folder arrangement meant it wasn't a problem to
write them in 2 sessions. Having everthing on one DVD is much better than
four CDs.  :-)

Easy to work around in most cases and until I fit an even bigger HD I might
not have enough space to write one enormous ISO file.

I was using an XP laptop to edit some of my diving video and the app creates
one huge file which is not the best idea since it cannot be copied onto FAT32.
Such an app should have chopped each video section into separate files making
it much easier to handle all round. I gather FAT32 is limited to (2^32) -1
bytes but GEMDOS halves that limit since it doesn't use the M$ kludge.
I once saw a similar kludge used to handle dates that had been stored in 8-bit
integer.

http://www.windowsitpro.com/article/file-systems/understanding-file-size-limits-on-ntfs-and-fat.aspx

Peter