Seems CONFIG_LBDAF was barking up the wrong tree. It is set on the i386 build, and does not apply to amd64.
** Summary changed: - Need CONFIG_LBDAF set to prevent silent wraparound on > 2 TB disks + Silent wraparound on > 2 TB disks ** Changed in: linux (Ubuntu) Status: Triaged => New ** Description changed: Ubuntu kernels silently wrap access to disk locations above 2 TB back around to zero. This can easily be reproduced using lvm to create a thin provisioned virtual disk: lvcreate --type zero -L 3t -n empty vg0 lvcreate -s -n thin vg0/zero -L 1g mke2fs -t ext4 -E lazy_itable_init /dev/vg0/thin e2fsck -f /dev/vg0/thin Fsck will find errors in the bitmap because it is actually reading the superblock instead of the allocation bitmap situated just after the 2 tb - mark. I emailed the dm-devel mailing list about the issue and was told - that this happens when CONFIG_LBDAF is not set, and that it would be - rather daft of a distribution not to set that option. I checked my - config for kernel 2.6.32-22-generic on lucid amd64 and indeed, this - option does not seem to be there. I also first observed this bug on - i386 karmic. - - I believe that this bug effects all users who have a > 2tb disk, be it - virtual, physical, or raid, and can lead to unexplained loss of data. - Therefore I feel it meets the criteria for a high priority bug, if not - critical. + mark. -- Silent wraparound on > 2 TB disks https://bugs.launchpad.net/bugs/593086 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs