newfs_lfs —
construct a new LFS file system
  
    | newfs_lfs | [newfs_lfs-options]
      special | 
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
  sgs fields are 1024, 8192, and 7 respectively.
The following options define the general layout policies.
  - -A
- Attempt to compute the appropriate segment size using the formula
      4 * bandwidth * access time. The disk is tested for
      twenty seconds to discover its bandwidth and seek time.
- -Blogical-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.
- -bblock-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.
- -F
- Force creation of an LFS even on a partition labeled as another type.
      newfs_lfswill use compile-time default values for
      block and fragment size, and segment shift, unless these are overridden by
      command-line flags.
- -ffragment-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.
- -Iinterleave
- Specify the interleave between segments. The default is zero.
- -i
- The size of an inode block, in bytes. The default is to use the same size
      as a fragment, or in a v1 filesystem, the same size as a data block.
- -L
- Create a log-structured file system (LFS). This is the default, and this
      option is provided for compatibility only.
- -Mnsegs
- Specify lfs_minfreeseg, the number of segments left out
      of the amount allocated to user data. A higher number increases cleaner
      performance, while a lower number gives more usable space. The default is
      based on the size of the filesystem, either 5% of the total number of
      segments or 20 segments, whichever is larger.
- -mfree space %
- The percentage of space reserved from normal users; the minimum free space
      threshold. The default value used is 10%.
- -N
- Do not actually create the filesystem.
- -Ooffset
- Start the first segment this many sectors from the beginning of the
      partition. The default is zero.
- -Rnsegs
- Specify lfs_resvseg, the number of segments set aside
      for the exclusive use of the cleaner. A larger figure reduces the
      likelihood of running out of clean segments, but if
      lfs_resvseg is too close to
      lfs_minfreeseg, the cleaner will run without ceasing
      when the filesystem becomes close to full. The default is the larger of 15
      or the quantity lfs_minfreeseg / 2 + 1 .
- -rident
- For a v2 filesystem, specify the roll-forward identifier for the
      filesystem. This identifier, a 32-bit numeric quantity, should be
      different from that of any LFS that may previously have existed on the
      same disk. By default the identifier is chosen at random.
- -ssize
- The size of the file system in sectors.
- -vversion
- Make a filesystem with the specified disk layout version. Valid options
      are 1 or 2 (the default). Note, however, that LFS
      version 1 is deprecated, and 64-bit volumes may not be version 1.
- -wbitwidth
- Create a filesystem using the specified bit width: 32 or 64. 32-bit LFS
      volumes are limited to 2TB in size; 64-bit LFS volumes are not, but incur
      additional overhead from having larger metadata structures. The default is
      32-bit for volumes less than 1 TB, and 64-bit for larger volumes.
disktab(5),
  disklabel(8),
  diskpart(8),
  dumplfs(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.
J. Matthews,
    D. Roselli, A. Costello,
    R. Wang, and T. Anderson,
    Improving the Performance of Log-Structured File Systems
    with Adaptive Methods, Proceedings of the Sixteenth
    ACM SOSP, October 1997.
A newlfs command appeared in
  4.4BSD, and was renamed to
  newfs_lfs for NetBSD 1.4.