mkfs1b(1M) mkfs1b(1M)
NAME
mkfs1b - construct a file system
SYNOPSIS
mkfs1b special size [m n]
mkfs1b special proto
DESCRIPTION
mkfs1b constructs a file system by writing on the special
file special. In the first form of the command a numeric
size is given and mkfs1b builds a file system with a single
empty directory on it. The number of i-nodes is calculated
as a function of the filesystem size. M is an interleave
factor for building the freelist and n is a modulo for m.
See the example for usage.
Note: All filesystems should have a lost+found directory for
fsck(1M); this should be created for each file system by
running mklost+found(1M) in the root directory of a newly
created file system, after the file system is first mounted.
In bootstrapping, the second form of mkfs1b is sometimes
used. In this form, the file system is constructed
according to the directions found in the prototype file
proto. The prototype file contains tokens separated by
spaces or new lines. The first token is the name of a file
to be copied onto sector zero as the bootstrap program. The
second token is a number specifying the size of the created
file system. Typically it will be the number of blocks on
the device, perhaps diminished by space for swapping. The
next token is the number of i-nodes in the i-list. The next
set of tokens comprise the specification for the root file.
File specifications consist of tokens giving the mode, the
user ID the group ID, and the initial contents of the file.
The syntax of the contents field depends on the mode.
The mode token for a file is a 6 character string. The
first character specifies the type of the file. (The
characters -bcd specify regular, block special, character
special and directory files, respectively.) The second
character of the type is either u or - to specify set-user-
id mode or not. The third is g or - for the set-group-id
mode. The rest of the mode is a three digit octal number
giving the owner, group, and other read, write, execute
permissions, see chmod(1).
Two decimal number tokens come after the mode; they specify
the user and group IDs of the owner of the file.
If the file is a regular file, the next token is a pathname
whence the contents and size are copied.
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mkfs1b(1M) mkfs1b(1M)
If the file is a block or character special file, two
decimal number tokens follow which give the major and minor
device numbers.
If the file is a directory, mkfs1b makes the entries . and
.. and then reads a list of names and (recursively) file
specifications for the entries in the directory. The scan
is terminated with the token $.
A sample prototype specification follows:
/usr/mdec/uboot
4872 55
d--777 3 1
usr d--777 3 1
sh ---755 3 1 /bin/sh
ken d--755 6 1
$
b0 b--644 3 1 0 0
c0 c--644 3 1 0 0
$
$
EXAMPLE
mkfs1b /dev/fd0 2000 7 50
makes a file system in which 2000 is the total size of the
file system to be put on /dev/fd0; 7 is a sector interleave
number which is used to stagger the disk blocks for more
rapid reading, every 7 blocks, and 50 is a modulo operator
that forces the sector interlace number first to allocate
all blocks in the first 50 sectors, then the next 50, etc.
NOTE: The proper selection of the m and n parameters can
improve disk efficiency. Disks which have full or partial
track buffering should specify a m and n of 1 and 1. M and n
for other disks must be determined by trial and error as the
disk latency is related to rotational latency and cpu speed.
FILES
/etc/mkfs1b
SEE ALSO
fsck(1M), mklost+found(1M), dir(4).
BUGS
The default is 3500, which is probably not useful on any
disk.
There should be some way to specify links.
There should be some way to specify bad blocks.
Should make lost+found automatically.
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