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

     newfs -- construct	a new UFS1/UFS2	file system

     newfs [-NUln] [-L volname]	[-O filesystem-type] [-S sector-size]
	   [-T disktype] [-a maxcontig]	[-b block-size]
	   [-c blocks-per-cylinder-group] [-d max-extent-size] [-e maxbpg]
	   [-f frag-size] [-g avgfilesize] [-h avgfpdir] [-i bytes]
	   [-m free-space] [-o optimization] [-s size] special

     The newfs utility is used to initialize and clear file systems before
     first use.	 Before	running	newfs the disk must be labeled using
     bsdlabel(8).  The newfs utility builds a file system on the specified
     special file.  (We	often refer to the "special file" as the "disk", al-
     though the	special	file need not be a physical disk.  In fact, it need
     not even be special.)  Typically the defaults are reasonable, however
     newfs has numerous	options	to allow the defaults to be selectively	over-

     The following options define the general layout policies:

     -L	volname
	     Add a volume label	to the new file	system.

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

     -O	filesystem-type
	     Use 1 to specify that a UFS1 format file system be	built; use 2
	     to	specify	that a UFS2 format file	system be built.  The default
	     format is UFS2.

     -T	disktype
	     For backward compatibility.

     -U	     Enable soft updates on the	new file system.

     -a	maxcontig
	     Specify the maximum number	of contiguous blocks that will be laid
	     out before	forcing	a rotational delay.  The default value is 16.
	     See tunefs(8) for more details on how to set this option.

     -b	block-size
	     The block size of the file	system,	in bytes.  It must be a	power
	     of	2.  The	default	size is	16384 bytes, and the smallest allow-
	     able size is 4096 bytes.  The optimal block:fragment ratio	is
	     8:1.  Other ratios	are possible, but are not recommended, and may
	     produce poor results.

     -c	blocks-per-cylinder-group
	     The number	of blocks per cylinder group in	a file system.	The
	     default is	to compute the maximum allowed by the other parame-
	     ters.  This value is dependent on a number	of other parameters,
	     in	particular the block size and the number of bytes per inode.

     -d	max-extent-size
	     The file system may choose	to store large files using extents.
	     This parameter specifies the largest extent size that may be
	     used.  It is presently limited to its default value which is 16
	     times the file system blocksize.

     -e	maxbpg
	     Indicate the maximum number of blocks any single file can allo-
	     cate out of a cylinder group before it is forced to begin allo-
	     cating 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	frag-size
	     The fragment size of the file system in bytes.  It	must be	a
	     power of two ranging in value between blocksize/8 and blocksize.
	     The default is 2048 bytes.

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

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

     -i	bytes
	     Specify the density of inodes in the file system.	The default is
	     to	create an inode	for every (4 * frag-size) bytes	of data	space.
	     If	fewer inodes are desired, a larger number should be used; to
	     create more inodes	a smaller number should	be given.  One inode
	     is	required for each distinct file, so this value effectively
	     specifies the average file	size on	the file system.

     -l	     Enable multilabel MAC on the new file system.

     -m	free-space
	     The percentage of space reserved from normal users; the minimum
	     free space	threshold.  The	default	value used is defined by
	     MINFREE from <ufs/ffs/fs.h>, currently 8%.	 See tunefs(8) for
	     more details on how to set	this option.

     -n	     Do	not create a .snap directory on	the new	file system.  The re-
	     sulting file system will not support snapshot generation, so
	     dump(8) in	live mode and background fsck(8) will not function
	     properly.	The traditional	fsck(8)	and offline dump(8) will work
	     on	the file system.  This option is intended primarily for	memory
	     or	vnode-backed file systems that do not require dump(8) or
	     fsck(8) support.

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

     -s	size
	     The size of the file system in sectors.  This value defaults to
	     the size of the raw partition specified in	special	(in other
	     words, newfs will use the entire partition	for the	file system).

     The following options override the	standard sizes for the disk geometry.
     Their default values are taken from the disk label.  Changing these de-
     faults 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 any of these	values from their defaults will	make it	impos-
     sible for fsck(8) to find the alternate superblocks if the	standard su-
     perblock is lost.

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

	   newfs /dev/ad3s1a

     Creates a new ufs file system on ad3s1a.  The newfs utility will use a
     block size	of 16384 bytes,	a fragment size	of 2048	bytes and the largest
     possible number of	blocks per cylinders group.  These values tend to pro-
     duce better performance for most applications than	the historical de-
     faults (8192 byte block size and 1024 byte	fragment size).	 This large
     fragment size may lead to much wasted space on file systems that contain
     many small	files.

     fdformat(1), disktab(5), fs(5), bsdlabel(8), camcontrol(8), dump(8),
     dumpfs(8),	fsck(8), mount(8), tunefs(8), vinum(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).

     The newfs utility appeared	in 4.2BSD.

BSD			       January 21, 2005				   BSD


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