mkfs(1M) (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
mkfs [ -F ufs ] [generic_options] [-o N] special size [nsect ntrack
bize fragsize cgsize free rps nbpi opt apc gap]
DESCRIPTION
generic_options are options supported by the generic mkfs command.
current_options are options supported by the s5-specific module of
the 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 the ufs specific suboptions in a comma-separated list
of suboptions. The following suboptions 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 The number of sectors per track on the disk. The default
is 36.
ntrack
The number of tracks per cylinder on the disk. The
default is 9.
bsize The primary block size for files on the file system. It
must be a power of two, currently selected from 4096 or
8192 (the default).
fragsize
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.
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mkfs(1M) (UFS) mkfs(1M)
cgsize
The number of disk cylinders per cylinder group. This
number must be in the range 1 to 32. The default is 16.
cgsize must be a multiple of the cylinder cycle size,
which is a power of 2 between 16 and 1. The cylinder
cycle size is calculated from nsect, ntrack and bsize.
free 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 The rotational speed of the disk, in revolutions per
second. The default is 60.
nbpi 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 Space or time optimization preference; s specifies
optimization for space, t specifies optimization for
time. The default is t.
apc The number of alternates per cylinder (SCSI devices
only). The default is 0.
gap 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.
EXAMPLE
mkfs -F ufs -o bsize=4096, nsect=18, ntrack=9 /dev/dsk/c8d1s1 35340
or
mkfs -F ufs /dev/dsk/c8d1s1 35340 36 9 4096 1024 16 10 60 2048 t 0 0
Note in the second usage all of the specific_options must be listed.
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), ufs(4).
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