mkfs(8)mkfs(8)Namemkfs - construct a file system
Syntax
/etc/mkfs [ -N ] special size [ nsect ] [ ntrack ] [ blksize ]
[ fragsize ] [ ncpg ] [ minfree] [ rps ] [ nbpi ] [ opt ]
Description
File systems are normally created with the command.
The -N option is used to run in no update mode. In this mode, will not
write to
The command constructs a file system by writing on the special file
special. The numeric size specifies the number of sectors in the file
system. The command builds a file system with a root directory and a
lost+found directory. For further information, see The number of i-
nodes is calculated as a function of the file system size. No boot
program is initialized by For further information, see
When the on-disks inodes of the file system are written, each contains
a unique number in its generation number field. This number uniquely
identifies each inode in a file system.
The optional arguments allow fine tune control over the parameters of
the file system. The nsect argument specifies the number of sectors
per track on the disk. The ntrack argument specifies the number of
tracks per cylinder on the disk. The blksize argument gives the pri‐
mary block size for files on the file system. It must be a power of
two, currently selected from 4096 or 8192. The fragsize argument gives
the fragment size for files on the file system. The fragsize argument
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 ncpg argument specifies the number of disk cylinders
per cylinder group. This number must be in the range 1 to 32. The
minfree argument specifies the minimum percentage of free disk space
allowed. Once the file system capacity reaches this threshold, only
the superuser is allowed to allocate disk blocks. The default value is
10%. If a disk does not revolve at 60 revolutions per second, the rps
parameter may be specified. Users with special demands for their file
systems are referred to ``A Fast File System for UNIX'' in the ULTRIX
Supplementary Documents, Volume 3: System Manager for a discussion of
the tradeoffs in using different configurations. The nbpi argument
specifies the number (ratio) of bytes per inode. The default is 2048
bytes. The opt argument is used to indicate the whether the file sys‐
tem should optimize for space or time. The opt argument can be
assigned a value of s or t.
Restrictions
If is invoked without arguments, the RISC machines dump core instead of
returning an error.
If the user-specified value for nbpi exceeds the maximum value allowed,
the user is not notified by (or by ).
See Alsodir(5), fs(5), fsck(8), newfs(8), tunefs(8)
"A Fast File System for UNIX", Supplementary Documents, Volume 3: Sys‐
tem Manager
mkfs(8)