Looking at the strace which Philipp provided, what is happening is that an exclusive open of the device is returning EBUSY from the kernel:
open("/dev/sdb1", O_RDONLY|O_EXCL) = -1 EBUSY (Device or resource busy) This means that either (a) the device is mounted, (b) some other program has the device open, or (c) /dev/sdb1 is being used as part of a RAID device by md, or (d) it is being used as a physical volume by LVM. In any case, this isn't an e2fsck bug. The kernel is returning EBUSY; e2fsck is refusing to check the file system because in any of the above situations, it is dangerous to proceed. Why that's the case, you would have to debug the system init scripts and/or any whacko upstartd or systemd setups. All I can tell you is that with Ubuntu 10.04 and Debian Testing using system V init script, it works just fine for me. I would recommend using lsof to see what other daemon or program might be holding /dev/sdb1 open. And also double checking to make sure /dev/sdb1 isn't being used by md or lvm. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/711799 Title: e2fsprogs wrongly identifies ext4 as mounted To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/e2fsprogs/+bug/711799/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs