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newfs(8)							      newfs(8)

NAME
       newfs, mfs - Constructs a new UFS file system

SYNOPSIS
       /usr/sbin/newfs [-N] [newfs-options] special-device [disk-type]

       /usr/sbin/mfs   [-F   mount-options]  [newfs-options]  [special-device]
       mount-node

OPTIONS
       This section describes the file system dependencies for	the  UFS  file
       systems.

       Displays the file system parameters without creating the file system.

       The  following  newfs-options  define the general layout policies.  The
       block size of the file system in bytes.	Note that the  block  size  is
       fixed at 8KB.  The fragment size of the file system in bytes.  The per‐
       centage of space reserved from normal users;  the  minimum  free	 space
       threshold  (minfree).  The default value is 10%. See tunefs(8) for more
       details on how to set this option.  Allows a user to  set  the  permis‐
       sions  on  the mfs root directory when it is first created. By default,
       the mode is set to 1777.	 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  is  less
       than 10%, the default is to optimize for space; if the value of minfree
       is greater than or equal to 10%, the default is to optimize  for	 time.
       See  tunefs(8) for more details on how to set this option.  This speci‐
       fies the maximum number of contiguous blocks that are laid  out	before
       forcing	a rotational delay (refer to the -d option); that is, the num‐
       ber of blocks that can be combined into a single	 read  request	(clus‐
       ter). The default value is 8.  See tunefs(8) for more details on how to
       set this option.	 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 zero  milliseconds.   See	tunefs(8)  for
       more  details  on  how  to set this option.  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 cylin‐
       der  group.  See	 tunefs(8) for more details on how to set this option.
       This specifies the density of inodes in the file system. The default is
       to  create  an inode for each 4096 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.  The number of cylinders per cylinder
       group in a file system.	The default value is 16.  The size of the file
       system in sectors.

       The following options override the default sizes for the disk geometry.
       The default values are taken from the disk label. Changing the defaults
       is  useful  only if you are using newfs to build (create) a file system
       whose raw image will eventually be used on a different type of disk (on
       a write-once disk, for example). Note that changing any of these values
       from their defaults makes it impossible for fsck to find the  alternate
       superblocks  if the standard superblock is lost.	 The speed of the disk
       in revolutions per minute.  The size of a sector in bytes (almost never
       anything	 but 512).  The number of sectors per 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 -p).  The num‐
       ber of tracks per cylinder available for data allocation	 by  the  file
       system.	 Spare	sectors (bad sector replacements) are physical sectors
       that occupy space at the end of each track. They	 are  not  counted  as
       part  of the sectors per track (-u) since they are not available to the
       file system for data allocation.	 Spare sectors	(bad  sector  replace‐
       ments)  are  physical  sectors that occupy space at the end of the last
       track in the cylinder. They are deducted from  the  sectors  per	 track
       (-u) of the last track of each cylinder since they are not available to
       the file system for data allocation.  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 layout, while 1/2
	      implies logical sector 0 (zero) is separated by one sector  from
	      logical  sector  1.  Used to describe perturbations in the media
	      format to compensate for a slow controller. Track	 skew  is  the
	      offset of sector 0 (zero) on track N relative to sector 0 (zero)
	      on track N-1 on the same cylinder.  This option applies only  to
	      mfs.  It	is  used  for  providing a decimal numeric value to be
	      passed as mount options when running as a memory based file sys‐
	      tem.   This  option  is  primarily  intended for use when mfs is
	      started by the mount(8) command.

DESCRIPTION
       The newfs command creates a new UFS file system on the  specified  spe‐
       cial-device of type disk-type.

					Note

       The newfs command cannot be used to create Advanced File System (AdvFS)
       domains. Instead, use the mkfdmn command, as described in the mkfdmn(8)
       reference page.

       Use  the disklabel command to label disks and the newfs command to cre‐
       ate UFS file systems on the disks.

       If you have labeled the disk by	using  the  disklabel  command,	 newfs
       builds  a  UFS file system on the specified device, basing its defaults
       on the information in the disk label.  If the disk has not been labeled
       using the disklabel command, newfs fails, displaying the message

       disk  not  labeled.   When  this	 happens, use the disklabel command to
       install a label.

       The mfs command builds a memory file system (mfs), which is a UFS  file
       system  in  virtual  memory, and mounts it on the specified mount-node.
       When the file system is unmounted, mfs exits and the  contents  of  the
       file system are lost.  If mfs is sent a signal while running, for exam‐
       ple during system shutdown, it attempts to  unmount  its	 corresponding
       file  system.   The parameters for mfs are almost the same as those for
       newfs.  For a memory file system, the special-device file provides only
       a  set  of  configuration parameters, including the size of the virtual
       memory segment to allocate.  If the special-device file is omitted, you
       must  specify the segment size.	The special-device file is usually the
       primary swap area, because that is where the file system is  backed  up
       when free memory gets low and the memory supporting the file system has
       to be paged.

       You can enable /tmp as a memory file system by adding an entry  in  the
       /etc/fstab  file. For example, the following line creates a 10 Megabyte
       memory file system, mounted on /tmp:

	    -s20480	   /tmp	  mfs rw 1 0

       Note that the contents of a memory file	system	are  lost  whenever  a
       reboot or unmount is performed.

       You must be superuser to use both commands.

NOTES
       When  using  newfs to create a UFS file system on an LSM volume, follow
       these guidelines: The disk-type variable may  be	 specified  to	enable
       newfs  to obtain disk attributes such as number of sectors (ns), number
       of tracks (nt), and number of  cylinders	 (nc)  from  the  /etc/disktab
       file.  The  newfs  command  may	get this information from /etc/disktab
       because an LSM volume has no disk label.	  When	specifying  disk-type,
       you  can use any entry in /etc/disktab that has positive values for the
       disk attributes (except rx## entries). Since the entries for disks with
       dynamic	geometry  (such as RAID, re, SWXCR, and hsz##) have a value of
       -1 for these attributes, such disk types cannot be specified to	newfs.
       Instead,	 use  another  entry  whose characteristics match those of the
       volume (for example, rz##).  Or, you can create a customized  entry  in
       /etc/disktab.   The -s option can be omitted, because newfs queries LSM
       for the size of the LSM volume.

ERRORS
       You may receive the following messages when using  the  newfs  command:
       newfs: /dev/rvol/diskgroup/volname: only 0 partitions

	      This error occurs when you attempt to create a file system on an
	      LSM volume and fail to  specify  the  disk-type  parameter  cor‐
	      rectly.  See  the	 NOTES	section for details.  Warning: nn sec‐
	      tor(s) in last cylinder unallocated

	      This message is for UFS only.  It requires no user  action.  The
	      message  indicates  that	if nn sectors are added to the size of
	      the file system, it will be an  integral	number	of  cylinders.
	      Disk  space  is  not  wasted.   Usually, cylinder boundaries are
	      ignored  when  partitions	  are	allocated.    Warning:	 inode
	      blocks/cyl  group	 (inumber)  >=	data  blocks (dnumber) in last
	      cylinder group. This implies snumber sector(s) cannot  be	 allo‐
	      cated

	      This  message requires no user action. It indicates that inumber
	      of file system blocks were needed to allocate  the  inode	 table
	      but  only	 dnumber  of  file system blocks were available in the
	      last cylinder group. The last cylinder group could not be	 allo‐
	      cated and snumber of sectors are actually wasted.	 Warning: spe‐
	      cial-device and overlapping partition(s) are marked in  use.  If
	      you  continue with the operation you can possibly destroy exist‐
	      ing data. CONTINUE? [y/n]

	      The specified partition overlaps with another partition or  par‐
	      titions  that  has  the fstype field set.	 Warning: partition(s)
	      which overlap special-device are marked in use. If you  continue
	      with  the operation you can possibly destroy existing data. CON‐
	      TINUE? [y/n]

	      The specified partition overlaps with another partition or  par‐
	      titions  that has the fstype field set.  Warning: special-device
	      is marked in use for fstype in the disklabel. The partition  you
	      are  changing  already  has  a file system on it. This is not an
	      error just a warning.

	      The partition you are changing already has a file system on  it.
	      special-device is marked in use for fstype in the disklabel.  If
	      you continue with the operation you can possibly destroy	exist‐
	      ing data.	 CONTINUE? [y/n]

	      This message indicates that you tried to create a file system on
	      a partition that is not currently in active use  but  is	marked
	      for use in the disk label's partition map. For example, the par‐
	      tition may be part of an LSM volume or an AdvFS domain.

	      If you know that the partition you specified to newfs  does  not
	      contain any useful data, you can choose to override the warning.
	      In this case, the fstype in the disk label will be  modified  to
	      4.2BSD.

	      Note that you can use the command disklabel -s to set the fstype
	      in the disk label to unused for partitions that do  not  contain
	      any  valid  data. See disklabel(8) for more information.	Parti‐
	      tion(s) which overlap special-device are marked in use.  If  you
	      continue	with  the  operation you can possibly destroy existing
	      data. CONTINUE? [y/n]

	      This message indicates that the partition you specified  is  not
	      marked  for  use,	 but other, overlapping partitions on the disk
	      are marked for use.  If you override this warning, the fstype in
	      the  disk's  label will be modified. The partition you specified
	      to newfs will be marked as in use by the	UFS  file  system  and
	      labeled  with 4.2BSD.  All overlapping partitions will be marked
	      UNUSED.  special-device

	      or an overlapping partition is open. Quitting...

	      This message indicates that you tried to create a file system on
	      a	 partition  that is actively in use.  Error: the disklabel for
	      special-device does not exist or is corrupted. Quitting ....

	      The specified device either does not have	 a  disklabel  or  the
	      disklabel is corrupted.  Error: special-device or an overlapping
	      partition is open. Quitting ....

	      This message indicates that you tried to create a file system on
	      a	 partition  that is open.  Error: special-device is an invalid
	      device or cannot be opened. Quitting ....

	      The specified device is either an invalid device or it cannot be
	      opened.	Error:	the  disklabel for special-device could not be
	      updated. Quitting ....

	      This message indicates  that  the	 disklabel  on	the  specified
	      device  could  not be updated.  Error:: unable to check special-
	      device  against  active  AdvFS  domains  because	the  directory
	      /etc/fdmns seems to be missing or wrong. Quitting ....

	      This  message  indicates	that there was a failure when checking
	      overlap with AdvFS domains. Either /etc/fdmns or	/etc/fdmns/dom
	      are  not	active domains or they do not exist.  Error: unable to
	      check special-device against active swap devices because special
	      swap files are missing. Quitting ....

	      This  message  indicates	that there was a failure when checking
	      overlap with active swap	devices.   The	special	 device	 files
	      associated with active swap devices are invalid.	Error: unknown
	      overlap  condition  errno	 encountered  for  partition  special-
	      device. Quitting ....

	      This message indicates that an unknown error was detected.

       The  following  examples	 illustrate some of these messages: Creating a
       file system on a partition that is marked for use:

	      # /usr/sbin/newfs /dev/rdisk/dsk11g

	      /dev/rdisk/dsk11g is marked in use for LSMpubl in the disklabel.
	      If  you  continue	 with  the  operation you can possibly destroy
	      existing data.  CONTINUE? [y/n]

	      Partition g of disk dsk11 is part of a disk marked  for  use  by
	      LSM.  If LSM is not actively using this partition and the parti‐
	      tion does not contain any useful data, you may want to  override
	      this  warning, by answering y. In this case, partition g will be
	      marked as 4.2BSD in the disk label.  Creating a file system on a
	      partition whose overlapping partitions are marked for use:

	      # /usr/sbin/newfs /dev/rdisk/dsk11c

	      Partition(s)  which overlap /dev/rdisk/dsk11c are marked in use.
	      If you continue with the	operation  you	can  possibly  destroy
	      existing data.  CONTINUE? [y/n]

	      If you answer y, partition c on disk dsk11 will be marked 4.2BSD
	      in the disk label and all partitions  that  overlap  c  will  be
	      marked  UNUSED.	Creating  a file system on a partition that is
	      open:

	      # /usr/sbin/newfs /dev/rdisk/dsk11g

	      /dev/rdisk/dsk11g or an overlapping partition  is	 open.	 Quit‐
	      ting...	Creating  a  file  system on disk that does not have a
	      disk label:

	      # /usr/sbin/newfs /dev/rdisk/dsk11c

	      The disklabel for /dev/rdisk/dsk11c does not exist  or  is  cor‐
	      rupted.  Quitting...

	      See disklabel(8) for information on installing a disk label on a
	      disk.

EXAMPLES
       The following examples show how to create  an  mfs  file	 system:  This
       example creates an mfs of 128 Mbytes mounted on /tmp:

	      #	 /usr/sbin/mfs	-s  250000 /tmp This example creates an mfs of
	      512 Mbytes (one half a Gbyte) mounted on /tmp:

	      #/usr/sbin/mfs -s 1000000 /tmp

FILES
       Specifies the command path.  Specifies the command path.	 Provides disk
       geometry and file system partition information.

SEE ALSO
       Commands:   chmod(1),   disklabel(8),   fsck(8),	 mkfdmn(8),  mount(8),
       tunefs(8)

       Files: disktab(4), fstab(4)

       Functions: check_usage(3), set_usage(3)

								      newfs(8)
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