I spent a few frustrating hours yesterday turning DVD+R blanks into coasters before I realised that there seems to be a deep problem with the whole DVD mechanism. Since this seems to be a bug in the philosophy of the system, rather than any specific module, I hope I can raise it safely here.
My root partition on this system contains about 6.2G of files. This includes things like the entire Hubble sky survey and the complete Ordnance Survey map database for the UK. Backing it up as a bzipped tar file gave me 2165096516 bytes of data. This is just over 2G - in fact it is hex 810CC044. I then burned this on DVD with growisofs.
When I mounted the resulting DVD the file had shrunk to 835652 bytes. This is in fact 000CC044. The "cruft" option had cut in and removed the high byte of the file length.
Now this is the problem: Is mkisofs/growisofs right to allow a file over 2G, and mount is wrong? Or is mount right, the top bit of the file length should never be set and mkisofs should have rejected it?
Either way it seems that as a DVD is longer than 4G there is no way, within the standard, of burning a DVD that contains a single 4.7G file.
So should I: 1) Report a bug in mkisofs? 2) Report a bug in mount? 3) Develop a workaround (I already have one)? 4) Use a different filesystem?
-- Robert Billing, Tanglewood, 01344-772849 64, Pinehill Road, rbilling@xxxxxxxxxxxxxxxxxxxx Crowthorne, http://www.tnglwood.demon.co.uk/ Berks, RG45 7JR
