** Attachment added: "user's boot sector" http://launchpadlibrarian.net/14818962/232175
** Description changed: When a FAT file system is written to a whole disk device, it appears rather like a DOS partition table in some ways. libparted therefore needs to detect this situation and explicitly bail out of treating it as a DOS partition table. However, its detection is a bit broken at the moment and has some false positives. Specifically, if the disk previously had a FAT file system covering its entire extent, but then had a partition table written to it, it can happen that the FAT signature is left around and confuses libparted. Both the Linux kernel and fdisk use a more reliable method, namely checking the boot indicator byte of all four partitions in the primary partition table to ensure that each one is either 0 or 0x80. libparted should be in sync with these. I sent a patch upstream (http://lists.alioth.debian.org/pipermail/parted- devel/2008-May/002243.html and thread) which has been accepted, and I uploaded this to intrepid as parted 1.7.1-5.1ubuntu10. Attached is the diff between 1.7.1-5.1ubuntu9 in hardy and the proposed 1.7.1-5.1ubuntu9.1. + + TEST CASE: This is a bit tricky to set up. The most obvious way is + probably to replicate the reporter's partition table on a loopback + device. To do this, download + http://launchpadlibrarian.net/14818962/232175, then: + + dd if=/dev/zero of=parted-test bs=1024 count=$((1100*1024)) + dd if=232175 of=parted-test bs=512 count=1 conv=notrunc + parted -s parted-test print + + With the old libparted1.7-1, this erroneously prints: + + Disk /home/cjwatson/parted-test: 1153MB + Sector size (logical/physical): 512B/512B + Partition Table: loop + + Number Start End Size File system Flags + 1 0.00kB 1153MB 1153MB fat32 + + The new one correctly prints: + + Disk /home/cjwatson/parted-test: 1153MB + Sector size (logical/physical): 512B/512B + Partition Table: msdos + + Number Start End Size Type File system Flags + 1 16.4kB 751MB 751MB primary boot + 2 751MB 1027MB 276MB primary + + Please also check that parted still understands your own partition table + correctly: 'sudo parted -s /dev/sda print', replacing /dev/sda with each + of whichever disk devices you have. + + Regression potential: We'll have to watch out for new partitioner bugs + of the form "partitions on this disk not recognised at all". However, + given that we're now in sync with the Linux kernel, I suspect that it's + more likely that any regressions would be FAT file systems erroneously + detected as partition tables (i.e. the other way round). It might be + worth trying this out with USB sticks. -- Partition tables sometimes misdetected as single large FAT file system https://bugs.launchpad.net/bugs/232175 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
