mkfs(8)
NAME
mkfs − construct a file system
SYNTAX
/etc/mkfs special size [ nsect ] [ ntrack ] [ blksize ] [ fragsize ] [ ncpg ]
[ minfree ] [ rps ] [ nbpi ]
DESCRIPTION
File system are normally created with the newfs(8) command.
The mkfs 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 mkfs command builds a file system with a root directory and a lost+found directory. For further information, see fsck(.). The number of i-nodes is calculated as a function of the file system size. No boot program is initialized by mkfs. For further information, see newfs(.).
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 specify the number of sectors per track on the disk. The ntrack specify the number of tracks per cylinder on the disk. The blksize gives the primary block size for files on the file system. It must be a power of two, currently selected from 4096 or 8192. The fragsize gives 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 ncpg specifies the number of disk cylinders per cylinder group. This number must be in the range 1 to 32. The minfree specifies the minimum percentage of free disk space allowed. Once the file system capacity reaches this threshold, only the super-user 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 the paper cited below for a discussion of the tradeoffs in using different configurations. nbpi specifies the number (ratio) of bytes per inode. The default is 2048 bytes.
SEE ALSO
dir(5), fs(5), fsck(8), newfs(8), tunefs(8)
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