In recent Linux kernels, the codice_6 functionality is implemented in the VFS layer, and is executed automatically when the Volume Manager's snapshot functionality is invoked. This was once a valuable advantage as the ext3 file system could not be suspended and the volume manager was unable to create a consistent "hot" snapshot to back up a heavily busy database. Fortunately this is no longer the case. Since Linux 2.6.29, the file systems ext3, ext4, GFS2 and JFS have the freeze feature as well.