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NetBSD 6.1.5 - man page for newfs (netbsd section 8)

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NEWFS(8)			   BSD 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] special

     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) suffix:
	   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 order.

     -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 speci-
		 fied with ``-s size''.  No attempts to use or update the disk label will be

     -f frag-size
		 The fragment size of the file system in bytes.  It must be a power of two rang-
		 ing 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 rec-
		 ommended, 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 'UFS2'.
		 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 interpre-

		 If no -s size is specified then the filesystem size defaults to that of the par-
		 tition, 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
		 The default is 3.  If -N is specified newfs stops before outputting the progress

     -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.  This is necessary if the image
		 is to be used by vnd(4) (which doesn't support file systems with 'holes').

     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) utility.

     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.

BSD					  June 30, 2012 				      BSD

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