[Jim, as coreutils developer, this might interest you] In libguestfs we run some quite detailed checks of the output of the statvfs system call for our tool "virt-df". I noticed that the output of virt-df changed slightly. Narrowing it down, the difference only happens between: Fedora kernel 3.2.0-0.rc0.git4.1.fc17 (3rd Nov) Fedora kernel 3.2.0-0.rc1.git2.1.fc17 (11th Nov) With 3.2.0-0.rc0.git4.1.fc17, and all earlier versions, the output of statvfs(2) on a freshly created 20M ext2 filesystem is: bsize: 1024 frsize: 1024 blocks: 19827 <-- NB bfree: 19655 bavail: 18631 files: 5136 ffree: 5125 favail: 5125 fsid: 1411286354856931562 flag: 4096 namemax: 255 With 3.2.0-0.rc1.git2.1.fc17, it changed to: bsize: 1024 frsize: 1024 blocks: 19939 <-- NB bfree: 19655 bavail: 18631 files: 5136 ffree: 5125 favail: 5125 fsid: -9088586685126948527 flag: 4096 namemax: 255 I am able to demonstrate the difference by keeping every other package identical, and just booting the two different kernels. As far as I know, everything else including e2fsprogs is completely identical. Reproducer: export FEBOOTSTRAP_KERNEL=/boot/vmlinuz-<version> guestfish sparse /tmp/test.img 20M : run : \ mkfs ext2 /dev/sda : mount /dev/sda / : statvfs / I tracked this down to the way the filesystem overhead is calculated. It changed slightly in the commit below. The description seems to be wrong; it seems to affect any filesystem going through the ext4 driver (this driver is used for ext2 & ext3 in recent Fedora), and doesn't appear to have anything to do with 'bigalloc'. commit f975d6bcc7a698a10cc755115e27d3612dcfe322 Author: Theodore Ts'o <tytso(a)mit.edu&gt; Date: Fri Sep 9 19:00:51 2011 -0400 ext4: teach ext4_statfs() to deal with clusters if bigalloc is enabled Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones New in Fedora 11: Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 70 libraries supprt'd http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw