MKFS.FFS(1M)        RISC/os Reference Manual         MKFS.FFS(1M)



NAME
     mkfs.ffs - construct a file system

SYNOPSIS
     /etc/mkfs.ffs [-N] special size [ nsect [ ntrack [ blksize [
     fragsize [ ncpg [ minfree [ rps [ nbpi
          [ opt ] ] ] ] ] ] ] ] ]

DESCRIPTION
     N.B.: file system are normally created with the newfs.ffs
     (1M) command.

     mkfs.ffs constructs a file system by writing on the special
     file special unless the -N flag has been specified.  The
     numeric size specifies the number of sectors in the file
     system.  mkfs.ffs builds a file system with a root directory
     and a lost+found directory.  (See fsck.ffs(1M).)  The number
     of i-nodes is calculated as a function of the file system
     size.  No boot program is initialized by mkfs.ffs (see
     newfs.ffs(1M)).

     The optional arguments allow fine tune control over the
     parameters of the file system.  nsect specifies the number
     of sectors per track on the disk.  ntrack specifies the
     number of tracks per cylinder on the disk.  blksize gives
     the primary block size for files on the file system.  It
     must be a power of two, currently selected from 4096 or
     8192.  fragsize gives the fragment size for files on the
     file system.  The fragsize represents the smallest amount of
     disk space that will be allocated to a file.  It must be a
     power of two currently selected from the range 512 to 8192.
     ncpg specifies the number of disk cylinders per cylinder
     group.  This number must be in the range 1 to 32.  minfree
     specifies the minimum percentage of free disk space allowed.
     Once the file system capacity reaches this threshold, only
     the super-user is allowed to allocate disk blocks.  The
     default value is 10%.  If a disk does not revolve at 60
     revolutions per second, the rps parameter may be specified.
     If a file system will have more or less than the average
     number of files the nbpi (number of bytes per inode) can be
     specified to increase or decrease the number of inodes that
     are created.  Space or time optimization preference can be
     specified with opt values of ``s'' for space or ``t'' for
     time.  Users with special demands for their file systems are
     referred to the paper cited below for a discussion of the
     tradeoffs in using different configurations.

SEE ALSO
     fsck.ffs(1M), newfs.ffs(1M), tunefs.ffs(1M), dumpfs.ffs(1M).
     fs.ffs(4), dir.ffs(4) in the Programmer's Reference Manual.
     Appendix A, A Fast File System For UNIX, in the System
     Administrator's Guide.



                        Printed 11/19/92                   Page 1

MKFS.FFS(1M)        RISC/os Reference Manual         MKFS.FFS(1M)



ERRORS
     There should be some way to specify bad blocks.





















































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