.\"	$NetBSD: newfs_lfs.8,v 1.12 2001/06/05 11:22:51 wiz Exp $
.\"
.\" Copyright (c) 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)newlfs.8	8.1 (Berkeley) 6/19/93
.\"
.Dd July 15, 1999
.Dt NEWFS_LFS 8
.Os
.Sh NAME
.Nm newfs_lfs
.Nd construct a new LFS file system
.Sh SYNOPSIS
.Nm
.Op Ar newfs_lfs-options
.Ar special
.Sh DESCRIPTION
.Nm
builds a log-structured file system on the specified special
device basing its defaults on the information in the disk label.
Before running 
.Nm
the disk must be labeled using 
.Xr disklabel 8 ,
the proper fstype is 4.4LFS.  Reasonable values for the
.Li fsize, 
.Li bsize,
and
.Li sgs
fields are 1024, 8192, and 7 respectively.
.Pp
The following options define the general layout policies.
.Bl -tag -width Fl
.It Fl A
Attempt to compute the appropriate segment size using the formula
\fB4 * bandwidth * access time\fR.  The disk is tested for twenty seconds
to discover its bandwidth and seek time. 
.It Fl B Ar logical-segment-size
The logical segment size of the file system in bytes.  If not specified,
the segment size is computed by left-shifting the partition label's block
size by the amount indicated in the partition table's segshift.  If the
disklabel indicates a zero block size or segment shift, a compile-time default
segment size of 1M is used.
.It Fl b Ar block-size
The block size of the file system in bytes.  If not specified, the block
size is taken from the partition label, or if the partition label
indicates 0, a compile-time default of 8K is used.
.It Fl F
Force creation of an LFS even on a partition labeled as another type.
.Nm
will use compile-time default values for block and fragment size, and segment
shift, unless these are overridden by command-line flags.
.It Fl f Ar fragment-size
The fragment size of the file system in bytes.  If not specified,
the fragment size is taken from the partition label, or if the partition
label indicates 0, a compile-time default of 1K is used.
.It Fl L
Create a log-structured file system (LFS).  This is the default, and this
option is provided for compatibility only.
.It Fl m Ar free space \&%
The percentage of space reserved from normal users; the minimum
free space threshold.  The default value used is 10%.
.It Fl M Ar nsegs
Reserve this many segments for use exclusively by the cleaner, instead
of letting
.Nm
do the computation.  Do not use this option.
.It Fl N
Do not actually create the filesystem.
.It Fl s Ar size
The size of the file system in sectors.
.El
.Sh SEE ALSO
.Xr disktab 5 ,
.\" .Xr fs 5 ,
.Xr dumplfs 8 ,
.Xr disklabel 8 ,
.Xr diskpart 8
.\" .Xr tunefs 8
.Rs
.%A M. Seltzer
.%A K. Bostic
.%A M. McKusick
.%A C. Staelin
.%T "An Implementation of a Log-Structured File System for UNIX"
.%J "Proceedings of the Winter 1993 USENIX Conference"
.%D January 25-29, 1993
.%P pp. 315-331
.Re
.Rs
.%A J. Matthews
.%A D. Roselli
.%A A. Costello
.%A R. Wang
.%A T. Anderson
.%T "Improving the Performance of Log-Structured File Systems with Adaptive Methods"
.%J "Proceedings of the Sixteenth ACM SOSP"
.%D October 1997
.Re
.Sh HISTORY
A \fBnewlfs\fR
command appeared in
.Bx 4.4 ,
and was renamed to 
.Nm
for
.Nx 1.4.