mkfs(1M)                      UNIX System V(UFS)                       mkfs(1M)


NAME
      mkfs (ufs) - construct a ufs file system

SYNOPSIS
      mkfs [ -F ufs ] [generic_options] special
      mkfs [ -F ufs ] [generic_options] [-o specific_options] special size

DESCRIPTION
      generic_options are options supported by the generic mkfs command.

      mkfs constructs a file system by writing on the special file special
      unless the `-o N' flag has been specified.  The numeric size specifies
      the number of sectors in the file system.  mkfs builds a file system with
      a root directory and a lost+found directory [see fsck(1M)].  The number
      of inodes is calculated as a function of the file system size.

      The options are:

      -F ufs
            Specifies the ufs-FSType.

      -o    Specify ufs file system specific options. The following options are
            available:

            N     Do not write the file system to the special file.  This
                  suboption gives all the information needed to create a file
                  system but does not create it.

            nsect=n
                  The number of sectors per track on the disk.  The default is
                  18.

            ntrack=n
                  The number of tracks per cylinder on the disk.  The default
                  is 9.

            bsize=n
                  The primary block size for files on the file system.  It must
                  be a power of two, currently selected from 4096 (the default)
                  or 8192.

            fragsize=n
                  The fragment size for files on the file system.  The fragsize
                  represents the smallest amount of disk space that will be
                  allocated to a file.  It must be a power of two currently
                  selected from the range 512 to 8192.  The default is 1024.

            cgsize=n
                  The number of disk cylinders per cylinder group.  This number
                  must be in the range 1 to 32.  The default is 16.




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mkfs(1M)                      UNIX System V(UFS)                       mkfs(1M)


            free=n
                  The minimum percentage of free disk space allowed.  Once the
                  file system capacity reaches this threshold, only a
                  privileged user is allowed to allocate disk blocks.  The
                  default value is 10%.

            rps=n The rotational speed of the disk, in revolutions per second.
                  The default is 60.

            nbpi=n
                  The number of bytes for which one inode block is allocated.
                  This parameter is currently set at one inode block for every
                  2048 bytes.

            opt=s|t
                  Space or time optimization preference; s specifies
                  optimization for space, t specifies optimization for time.
                  The default is t.

            apc=n The number of alternates per cylinder (SCSI devices only).
                  The default is 0.

            gap=n The expected time (in milliseconds) to service a transfer
                  completion interrupt and initiate a new transfer on the same
                  disk.  It is used to decide how much rotational spacing to
                  place between successive blocks in a file.  The default is 4.

NOTES
      The value of the nbpi operand in the output of mkfs -m is always 2048,
      even if the file system was created with some other value.

SEE ALSO
      fsck(1M), generic mkfs(1M), dir(4), fs(4)





















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