BSD 4_3_Reno development

[unix-history] / usr / share / man / cat8 / mfs.0

NEWFS(8)		      1990			 NEWFS(8)



N\bNA\bAM\bME\bE
     newfs, mfs - construct a new file system

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     n\bne\bew\bwf\bfs\bs [ -\b-N\bN ] [ n\bne\bew\bwf\bfs\bs-\b-o\bop\bpt\bti\bio\bon\bns\bs ] s\bsp\bpe\bec\bci\bia\bal\bl
     m\bmf\bfs\bs [ -\b-F\bF mount_flags ] [ n\bne\bew\bwf\bfs\bs-\b-o\bop\bpt\bti\bio\bon\bns\bs ] s\bsp\bpe\bec\bci\bia\bal\bl n\bno\bod\bde\be

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     _\bN_\be_\bw_\bf_\bs replaces the more obtuse _\bm_\bk_\bf_\bs(8) program.  Before run-
     ning _\bn_\be_\bw_\bf_\bs or _\bm_\bf_\bs, the disk must be labeled using _\bd_\bi_\bs_\bk_\bl_\ba_\b-
     _\bb_\be_\bl(8).  _\bN_\be_\bw_\bf_\bs 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 _\bn_\be_\bw_\bf_\bs
     has numerous options to allow the defaults to be selectively
     overridden.  The -\b-N\bN option causes the file system parameters
     to be printed out without really creating the file system.

     _\bM_\bf_\bs is used to build a file system in virtual memory and
     then mount it on a specified node.  _\bM_\bf_\bs exits and the con-
     tents of the file system are lost when the file system is
     unmounted.  If _\bm_\bf_\bs is sent a signal while running, for exam-
     ple during system shutdown, it will attempt to unmount its
     corresponding file system.  The parameters to _\bm_\bf_\bs are the
     same as those to _\bn_\be_\bw_\bf_\bs.  The special file is only used to
     read the disk label which provides a set of configuration
     parameters for the memory based file system.  The special
     file is typically that of the primary swap area, since that
     is where the file system will be backed up when free memory
     gets low and the memory supporting the file system has to be
     paged.

     The following options define the general layout policies.

     -\b-b\bb b\bbl\blo\boc\bck\bk-\b-s\bsi\biz\bze\be
	       The block size of the file system in bytes.

     -\b-f\bf f\bfr\bra\bag\bg-\b-s\bsi\biz\bze\be
	       The fragment size of the file system in bytes.

     -\b-m\bm f\bfr\bre\bee\be s\bsp\bpa\bac\bce\be %\b%
	       The percentage of space reserved from normal
	       users; the minimum free space threshold.  The
	       default value used is 10%.  See _\bt_\bu_\bn_\be_\bf_\bs(8) for more
	       details on how to set this option.

     -\b-o\bo o\bop\bpt\bti\bim\bmi\biz\bza\bat\bti\bio\bon\bn p\bpr\bre\bef\bfe\ber\bre\ben\bnc\bce\be (\b(`\b``\b`s\bsp\bpa\bac\bce\be'\b''\b' o\bor\br `\b``\b`t\bti\bim\bme\be'\b''\b')\b)
	       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 10%, the default is to optimize for space; if
	       the value of minfree greater than or equal to 10%,



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NEWFS(8)		      1990			 NEWFS(8)



	       the default is to optimize for time.  See
	       _\bt_\bu_\bn_\be_\bf_\bs(8) for more details on how to set this
	       option.

     -\b-a\ba m\bma\bax\bxc\bco\bon\bnt\bti\big\bg
	       This specifies the maximum number of contiguous
	       blocks that will be laid out before forcing a
	       rotational delay (see -d below).  The default
	       value is one.  See _\bt_\bu_\bn_\be_\bf_\bs(8) for more details on
	       how to set this option.

     -\b-d\bd r\bro\bot\btd\bde\bel\bla\bay\by
	       This specifies the expected time (in milliseconds)
	       to service a transfer completion interrupt and
	       initiate a new transfer on the same disk.  The
	       default is 4 milliseconds.  See _\bt_\bu_\bn_\be_\bf_\bs(8) for more
	       details on how to set this option.

     -\b-e\be m\bma\bax\bxb\bbp\bpg\bg 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 _\bt_\bu_\bn_\be_\bf_\bs(8) for more details on how to
	       set this option.

     -\b-i\bi n\bnu\bum\bmb\bbe\ber\br o\bof\bf b\bby\byt\bte\bes\bs p\bpe\ber\br i\bin\bno\bod\bde\be
	       This specifies the density of inodes in the file
	       system.	The default is to create an inode for
	       each 2048 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.

     -\b-c\bc #\b#c\bcy\byl\bli\bin\bnd\bde\ber\brs\bs/\b/g\bgr\bro\bou\bup\bp
	       The number of cylinders per cylinder group in a
	       file system.  The default value used is 16.

     -\b-s\bs s\bsi\biz\bze\be   The size of the file system in sectors.

     The following options override the standard sizes for the
     disk geometry. Their default values are taken from the disk
     label.  Changing these defaults is useful only when using
     _\bn_\be_\bw_\bf_\bs 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 impossible for _\bf_\bs_\bc_\bk to find the alternate
     superblocks if the standard super block is lost.

     -\b-r\br r\bre\bev\bvo\bol\blu\but\bti\bio\bon\bns\bs/\b/m\bmi\bin\bnu\but\bte\be
	       The speed of the disk in revolutions per minute.



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NEWFS(8)		      1990			 NEWFS(8)



     -\b-S\bS s\bse\bec\bct\bto\bor\br-\b-s\bsi\biz\bze\be
	       The size of a sector in bytes (almost never any-
	       thing but 512).

     -\b-u\bu s\bse\bec\bct\bto\bor\brs\bs/\b/t\btr\bra\bac\bck\bk
	       The number of sectors/track available for data
	       allocation by the file system.  This does not
	       include sectors reserved at the end of each track
	       for bad block replacement (see -\b-p\bp below).

     -\b-t\bt #\b#t\btr\bra\bac\bck\bks\bs/\b/c\bcy\byl\bli\bin\bnd\bde\ber\br
	       The number of tracks/cylinder available for data
	       allocation by the file system.

     -\b-p\bp s\bsp\bpa\bar\bre\be s\bse\bec\bct\bto\bor\brs\bs p\bpe\ber\br t\btr\bra\bac\bck\bk
	       Spare sectors (bad sector replacements) are physi-
	       cal sectors that occupy space at the end of each
	       track.  They are not counted as part of the
	       sectors/track (-\b-u\bu) since they are not available to
	       the file system for data allocation.

     -\b-x\bx s\bsp\bpa\bar\bre\be s\bse\bec\bct\bto\bor\brs\bs p\bpe\ber\br c\bcy\byl\bli\bin\bnd\bde\ber\br
	       Spare sectors (bad sector replacements) are physi-
	       cal sectors that occupy space at the end of the
	       last track in the cylinder.  They are deducted
	       from the sectors/track (-\b-u\bu) of the last track of
	       each cylinder since they are not available to the
	       file system for data allocation.

     -\b-l\bl h\bha\bar\brd\bdw\bwa\bar\bre\be s\bse\bec\bct\bto\bor\br i\bin\bnt\bte\ber\brl\ble\bea\bav\bve\be
	       Used to describe perturbations in the media format
	       to compensate for a slow controller.  Interleave
	       is physical sector interleave on each track,
	       specified as the denominator of the ratio:
		    sectors read / sectors passed over
	       Thus an interleave of 1/1 implies contiguous lay-
	       out, while 1/2 implies logical sector 0 is
	       separated by one sector from logical sector 1.

     -\b-k\bk s\bse\bec\bct\bto\bor\br 0\b0 s\bsk\bke\bew\bw,\b, p\bpe\ber\br t\btr\bra\bac\bck\bk
	       Used to describe perturbations in the media format
	       to compensate for a slow controller.  Track skew
	       is the offset of sector 0 on track N relative to
	       sector 0 on track N-1 on the same cylinder.

     The following option applies only to _\bm_\bf_\bs.

     -\b-F\bF m\bmo\bou\bun\bnt\bt f\bfl\bla\bag\bgs\bs
	       Used to pass in a decimal numeric value to be
	       passed as mount flags when running as a memory
	       based file system.  This option is primarily
	       intended for use when _\bm_\bf_\bs is started by the



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NEWFS(8)		      1990			 NEWFS(8)



	       _\bm_\bo_\bu_\bn_\bt(8) command.

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     disktab(5), fs(5), disklabel(8), diskpart(8), fsck(8), for-
     mat(8), tunefs(8)

     M. McKusick, W. Joy, S. Leffler, R. Fabry, ``A Fast File
     System for UNIX'', _\bA_\bC_\bM _\bT_\br_\ba_\bn_\bs_\ba_\bc_\bt_\bi_\bo_\bn_\bs _\bo_\bn _\bC_\bo_\bm_\bp_\bu_\bt_\be_\br _\bS_\by_\bs_\bt_\be_\bm_\bs _\b2,
     3.  pp 181-197, August 1984.  (reprinted in the System
     Manager's Manual, SMM:14)













































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