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NEWFS(8)                    System Manager's Manual                   NEWFS(8)

     newfs - construct a new file system

     newfs [-FGINZ] [-a maxcontig] [-B byte-order] [-b block-size]
           [-d maxbsize] [-e maxbpg] [-f frag-size] [-g avgfilesize]
           [-h avgfpdir] [-i bytes-per-inode] [-m free-space] [-n inodes]
           [-O filesystem-format] [-o optimization] [-q quota]
           [-S sector-size] [-s size] [-T disk-type] [-v volname] [-V verbose]

     newfs is used to initialize and clear file systems before first use.
     Before running newfs the disk must be labeled using disklabel(8).  newfs
     builds a file system on the specified special device basing its defaults
     on the information in the disk label.  Typically the defaults are
     reasonable, however newfs has numerous options to allow the defaults to
     be selectively overridden.

     Options with numeric arguments may contain an optional (case-insensitive)
           b    Bytes; causes no modification.  (Default)
           k    Kilo; multiply the argument by 1024.
           m    Mega; multiply the argument by 1048576.
           g    Giga; multiply the argument by 1073741824.
           t    Tera; multiply the argument by 1099511627776.

     The following options define the general layout policies.

     -a maxcontig
                 This sets the obsolete maxcontig parameter.

     -B byte-order
                 Specify the metadata byte order of the file system to be
                 created.  Valid byte orders are `be' and `le'.  If no byte
                 order is specified, the file system is created in host byte

     -b block-size
                 The block size of the file system, in bytes.  It must be a
                 power of two.  The smallest allowable size is 4096 bytes.
                 The default size depends upon the size of the file system:

                       file system size  block-size
                       < 20 MB           4 KB
                       < 1000 MB         8 KB
                       < 128 GB          16 KB
                       >= 128 GB         32 KB

     -d maxbsize
                 Set the maximum extent size to maxbsize.

     -e maxbpg   This indicates the maximum number of blocks any single file
                 can allocate out of a cylinder group before it is forced to
                 begin allocating blocks from another cylinder group.  The
                 default is about one quarter of the total blocks in a
                 cylinder group.  See tunefs(8) for more details on how to set
                 this option.

     -F          Create a file system image in special.  The file system size
                 needs to be specified with "-s size".  No attempts to use or
                 update the disk label will be made.

     -f frag-size
                 The fragment size of the file system in bytes.  It must be a
                 power of two ranging in value between block-size/8 and
                 block-size.  The optimal block-size:frag-size ratio is 8:1.
                 Other ratios are possible, but are not recommended, and may
                 produce unpredictable results.  The default size depends upon
                 the size of the file system:

                       file system size  frag-size
                       < 20 MB           0.5 KB
                       < 1000 MB         1 KB
                       < 128 GB          2 KB
                       >= 128 GB         4 KB

     -G          Treat garbage parameters as non-fatal.  Using this option may
                 result in a file system which causes a kernel panic and
                 should only be used for testing.

     -g avgfilesize
                 The expected average file size for the file system.

     -h avgfpdir
                 The expected average number of files per directory on the
                 file system.

     -I          Do not require that the file system type listed in the disk
                 label is `4.2BSD' or `Apple UFS'.

     -i bytes-per-inode
                 This specifies the density of inodes in the file system.  If
                 fewer inodes are desired, a larger number should be used; to
                 create more inodes a smaller number should be given.  The
                 default is to create an inode for every (4 * frag-size) bytes
                 of data space:

                       file system size  bytes-per-inode
                       < 20 MB           2 KB
                       < 1000 MB         4 KB
                       < 128 GB          8 KB
                       >= 128 GB         16 KB

     -m free-space
                 The percentage of space reserved from normal users; the
                 minimum free space threshold.  The default value used is 5%.
                 See tunefs(8) for more details on how to set this option.

     -N          Causes the file system parameters to be printed out without
                 really creating the file system.

     -n inodes   This specifies the number of inodes for the filesystem.  If
                 both -i and -n are specified then -n takes precedence.

     -O filesystem-format
                 Select the filesystem-format.
                       0    4.3BSD; This option is primarily used to build
                            root file systems that can be understood by older
                            boot ROMs.  This generates an FFSv1 file system
                            with level 1 format.
                       1    FFSv1; normal Fast File System, level 4 format.
                            Also known as `FFS', `UFS', or `UFS1'.  This is
                            the default.
                       2    FFSv2; enhanced Fast File System, suited for more
                            than 1 Terabyte capacity.  This is also known as
                       2ea  FFSv2 plus support for extended attributes and
                            access control lists.
                 See fsck_ffs(8) for more information about format levels.

                 To create an LFS filesystem see newfs_lfs(8).  To create a
                 Linux ext2 filesystem see newfs_ext2fs(8).

     -o optimization
                 Optimization preference; either "space" or "time".  The file
                 system can either be instructed to try to minimize the time
                 spent allocating blocks, or to try to minimize the space
                 fragmentation on the disk.  If the value of minfree (see
                 above) is less than 5%, the default is to optimize for space;
                 if the value of minfree is greater than or equal to 5%, the
                 default is to optimize for time.  See tunefs(8) for more
                 details on how to set this option.

     -q quota    enable a quota.  quota can be one of user or group to enable
                 the specified quota type.  Multiple -q can be used to enable
                 all types at once.

     -s size     The size of the file system in sectors.  An `s' suffix will
                 be interpreted as the number of sectors (the default).  All
                 other suffixes are interpreted as per other numeric
                 arguments, except that the number is converted into sectors
                 by dividing by the sector size (as specified by -S secsize)
                 after suffix interpretation.

                 If no -s size is specified then the filesystem size defaults
                 to that of the partition, or, if -F is specified, the
                 existing file.

                 If size is negative the specified size is subtracted from the
                 default size (reserving space at the end of the partition).

     -T disk-type
                 Uses information for the specified disk from /etc/disktab
                 instead of trying to get the information from the disk label.

     -V verbose  This controls the amount of information written to stdout:
                       0    No output.
                       1    Overall size and cylinder group details.
                       2    A progress bar (dots ending at right hand margin).
                       3    The first few super-block backup sector numbers
                            are displayed before the progress bar.
                       4    All the super-block backup sector numbers are
                            displayed (no progress bar).
                 The default is 3.  If -N is specified newfs stops before
                 outputting the progress bar.

     -v volname  This specifies that an Apple UFS filesystem should be created
                 with the given volume name.

     -Z          Pre-zeros the file system image created with -F.

     The following option overrides the standard sizes for the disk geometry.
     The default value is taken from the disk label.  Changing this default is
     useful only when using newfs to build a file system whose raw image will
     eventually be used on a different type of disk than the one on which it
     is initially created (for example on a write-once disk).  Note that
     changing this value from its default will make it impossible for
     fsck_ffs(8) to find the alternative superblocks if the standard
     superblock is lost.

     -S sector-size
                 The size of a sector in bytes (almost never anything but
                 512).  Defaults to 512.

     The file system is created with `random' inode generation numbers to
     improve NFS security.

     The owner and group IDs of the root node of the new file system are set
     to the effective UID and GID of the user initializing the file system.

     For the newfs command to succeed, the disk label should first be updated
     such that the fstype field for the partition is set to `4.2BSD' or `Apple
     UFS', unless -F or -I is used.

     To create and populate a filesystem image within a file use the makefs(8)

     The partition size is found using fstat(2), not by inspecting the disk
     label.  The block size and fragment size will be written back to the disk
     label only if the last character of special references the same partition
     as the minor device number.

     Unless -F is specified, special must be a raw device.  This means that
     for example wd0a or /dev/rwd0a must be specified instead of /dev/wd0a.

     fstat(2), disktab(5), fs(5), disklabel(8), diskpart(8), dumpfs(8),
     fsck_ffs(8), makefs(8), mount(8), mount_mfs(8), newfs_ext2fs(8),
     newfs_lfs(8), newfs_msdos(8), tunefs(8)

     M. McKusick, W. Joy, S. Leffler, and R. Fabry, "A Fast File System for
     UNIX,", ACM Transactions on Computer Systems 2, 3, pp 181-197, August
     1984, (reprinted in the BSD System Manager's Manual).

     M. McKusick, "Enhancements to the fast filesystem to support multi-
     terabyte storage systems", Proceedings of the BSD Conference 2003, pp
     79-90, September 2003.

     The newfs command appeared in 4.2BSD.

NetBSD 10.99                    April 13, 2019                    NetBSD 10.99