newfs_lfs(8) - NetBSD Manual Pages

NEWFS_LFS(8)            NetBSD System Manager's Manual            NEWFS_LFS(8)


NAME

     newfs_lfs - construct a new LFS file system


SYNOPSIS

     newfs_lfs [newfs_lfs-options] special


DESCRIPTION

     newfs_lfs builds a log-structured file system on the specified special
     device basing its defaults on the information in the disk label.  Before
     running newfs_lfs the disk must be labeled using disklabel(8), the proper
     fstype is 4.4LFS.  Reasonable values for the fsize, bsize, and cpg (real-
     ly sgs, segment shift) fields are 1024, 8192, and 7 respectively.

     The following options define the general layout policies.

     -B 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 ze-
                 ro block size or segment shift, a compile-time default seg-
                 ment size of 1M is used.

     -b block-size
                 The block size of the file system in bytes.  If not speci-
                 fied, the block size is taken from the partition label, or if
                 the partition label indicates 0, a compile-time default of 8K
                 is used.

     -F          Force creation of an LFS even on a partition labeled as an-
                 other type.  newfs_lfs will use compile-time default values
                 for block and fragment size, and segment shift, unless these
                 are overridden by command-line flags.

     -f fragment-size
                 The fragment size of the file system in bytes.  If not speci-
                 fied, the fragment size is taken from the partition label, or
                 if the partition label indicates 0, a compile-time default of
                 1K is used.

     -L          Create a log-structured file system (LFS).  This is the de-
                 fault, and this option is provided for compatibility only.

     -m free space %
                 The percentage of space reserved from normal users; the mini-
                 mum free space threshold.  The default value used is 10%.

     -M nsegs    Reserve this many segments for use exclusively by the clean-
                 er, instead of letting newfs_lfs do the computation.  Do not
                 use this option.

     -N          Do not actually create the filesystem.

     -s size     The size of the file system in sectors.


SEE ALSO

     disktab(5), dumplfs(8), disklabel(8), diskpart(8)

     M. Seltzer, K. Bostic, M. McKusick, and C. Staelin, "An Implementation of
     a Log-Structured File System for UNIX", Proceedings of the Winter 1993
     USENIX Conference, pp. 315-331, January 25-29, 1993.


HISTORY

     A newlfs command appeared in 4.4BSD, and was renamed to newfs_lfs for
     NetBSD 1.4.

4.4BSD                           July 15, 1999                               2