NEWFS(8) System Manager's Manual NEWFS(8)
newfs - construct a new file system
/sbin/newfs [ -N ] [ -m free-gap ] [ -n free-modulus ] [ -i bytes ] [ -s size ] [ -T disk-type ] special
Newfs is a ``friendly'' front-end to the mkfs(8) program. Newfs(8) will normally read the disklabel from the drive to determine the parti-
tion sizes. If the driver for the disk does not support disklabels the -T option must be used to force a search of /etc/disktab for parti-
tion information about drive-type. Newfs calculates the appropriate parameters to use in calling mkfs, then builds the file system by
-N causes the mkfs command which would be executed to be printed out without actually creating the file system. The disk specified by spe-
cial must be online though so that newfs can read the disklabel.
-m allows the specification of the block interleaving of the free list. If not specified or outside the range 1 thru 32 then a value of 2
-n parameter is the freelist modulus (when the -m pattern repeats) and is calculated by newfs to be 1 cylinder in size by default.
-i specifies how many bytes per inode to assume when calculating how many inodes to allocate. The default is 4096 bytes per inode. If
this results in too few inodes being allocated (there is an absolute maximum of 65500) then decrease the bytes number (which must lie
between 512 and 65536).
-T must be used if the disk specified by special has not been labeled with the disklabel(8) program. In this case disk-type is used by
getdisklabel(3) when searching /etc/disktab. This option is used when the underlying device driver does not support disklabels. Care must
be taken that the contents of /etc/disktab match the partition tables in the kernel.
-s specifies how many sectors the file system is to contain. There are two sectors per file system block, therefore size should be even.
This parameter must be less than or equal to the partition size (as determined from the disklabel or /etc/disktab). An error is printed
and no action is taken if the partition size is 0 or too large.
NOTE: Mkfs deals in units of filesystem blocks not sectors. Newfs uses sectors.
/etc/disktab disk geometry and partition information
mkfs to actually build the file system
getdisklabel(3), disklabel(8), disktab(5), diskpart(8), fs(5), fsck(8), mkfs(8)
newfs(8) no longer places boot blocks on the filesystem. That duty has been moved to the disklabel(8) program. If you must place a boot
block on a disk whose driver does not support disklabels use dd(1).
4.2 Berkeley Distribution April 12, 1996 NEWFS(8)