When file system administration commands have both specific and generic components (for example, fsck(1M)), the file system type must be specified. If it is not explicitly specified using the -F FSType command line option, the generic command looks in /etc/vfstab in order to determine the file system type, using the supplied raw or block device or mount point. If the file system type can not be determined by searching /etc/vfstab, the command will use the default file system type specified in either /etc/default/fs or /etc/dfs/dfstypes, depending on whether the file system is local or remote.
The default local file system type is specified in /etc/default/fs by a line of the form LOCAL=fstype (for example, LOCAL=ufs). The default remote file system type is determined by the first entry in the /etc/dfs/fstypes file.
File system administration commands will determine whether the file system is local or remote by examining the specified device name. If the device name starts with ``/'' (slash), it is considered to be local; otherwise it is remote.
The default file system types can be changed by editing the default files with a text editor.
/etc/vfstab list of default parameters for each file system
/etc/default/fs the default local file system type
/etc/dfs/fstypes the default remote file system type
fsck(1M), fstypes(4), vfstab(4)