I'd like to understand what are the pitfalls, if any, in using multi-extent files, as enabled by mkisofs "--iso-level 3" option for files larger than 4GiB-2, on Linux.
I'm using - mkisofs 2.01.01a69 - kernel 2.6.18-164.9.1.el5 (RHEL5) ==== I had made some tests and it seemed to me the kernel I was using was OK. However, yesterday I read Thomas Schmitt message http://lists.debian.org/cdwrite/2010/01/msg00072.html "..My 2.6.18 swallows the last few bytes if the file size is not a multiple of 2048...." So I looked the git history for isofs/inode.c. Kernel 2.6.18 was released on 2006-09-20. Then on 2009-09-27 this patch was applied "[PATCH] I/O Error attempting to read last partial block of a file in an ISO9660 file... " http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6-stable.git;a=commit;h=fb50ae7446abb35184be029c51f825e45a4e0670 which seems to have to do with multi-extent files. This patch is not in the RHEL5 kernel, so it should still has this defect. I don't see any other relevant patch in the inode.c history log http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6-stable.git;a=history;f=fs/isofs/inode.c;h=6b4dcd4f2943e632c9d89115a2395084be95adc5;hb=HEAD === Still, this simple test shows the file is read back OK on RHEL5 2.6.18 kernel; the file is larger than 4GiB-2 and not multiple of 2048: ----- dd if=/dev/urandom of=filetest bs=1000000 count=4300 mkisofs -quiet --iso-level 3 -o test.iso filetest sudo mount -o loop test.iso /mnt/cdrom md5sum /mnt/cdrom/filetest md5sum filetest (the 2 md5sum come back the same) ----- How can I test multi-extent file hadling effectively? I have to stay on RHEL5 kernel I cannot patch or upgrade the kernel. Thanks. -- giul...@pobox.com -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@other.debian.org