What: lvcreate -s -n snap -L 1g vg/root hangs in an unkillable state while trying to flush the fs and suspend the device to switch tables over to the snapshot, and no further IO is possible so the system must be hard booted with magic-sysrq. Where: 2.6.35, all 3 release candidates. 2.6.34 and earlier kernels are fine.