MKFS(1M) INTERACTIVE UNIX System MKFS(1M)
NAME
mkfs - construct a file system
SYNOPSIS
/etc/mkfs special blocks[:inodes] [gap blocks/cyl] [-b
blocksize]
/etc/mkfs special proto [gap blocks/cyl] [-b blocksize]
DESCRIPTION
mkfs constructs a file system by writing on the special file
using the values found in the remaining arguments of the
command line. The command waits 10 seconds before starting
to construct the file system. During this 10-second pause
the command can be aborted by entering a delete (DEL).
The -b blocksize option specifies the logical block size for
the file system. The logical block size is the number of
bytes read or written by the operating system in a single
I/O operation. Valid values for blocksize are 512, 1024,
and 2048. The default is 1024. A block size of 2048 may be
chosen only if the 2K file system package is installed. If
the -b option is used, it must appear last on the command
line.
If the second argument to mkfs is a string of digits, the
size of the file system is the value of blocks interpreted
as a decimal number. This is the number of physical (512-
byte) disk blocks the file system will occupy. If the
number of inodes is not given, the default is approximately
the number of logical blocks divided by 4. mkfs builds a
file system with a single empty directory on it. The boot
program block (block zero) is left uninitialized.
If the second argument is the name of a file that can be
opened, mkfs assumes it to be a prototype file proto, and
will take its directions from that file. The prototype file
contains tokens separated by spaces or new-lines. A sample
prototype specification follows (line numbers have been
added to aid in the explanation):
1. /stand/ diskboot
2. 4872 110
3. d--777 3 1
4. usr d--777 3 1
5. sh ---755 3 1 /bin/sh
6. ken d--755 6 1
7. $
8. b0 b--644 3 1 0 0
9. c0 c--644 3 1 0 0
10. $
11. $
Line 1 in the example is the name of a file to be copied
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onto block zero as the bootstrap program.
Line 2 specifies the number of physical (512-byte) blocks
the file system is to occupy and the number of inodes in the
file system.
Lines 3-9 tell mkfs about files and directories to be
included in this file system.
Line 3 specifies the root directory.
Lines 4-6 and 8-9 specify other directories and files.
The $ on line 7 tells mkfs to end the branch of the file
system it is on, and continue from the next higher direc-
tory. The $ on lines 10 and 11 end the process, since no
additional specifications follow.
File specifications give the mode, the user ID, the group
ID, and the initial contents of the file. Valid syntax for
the contents field depends on the first character of the
mode.
The mode for a file is specified by a 6-character string.
The first character specifies the type of the file. The
character range is -bcd to specify regular, block special,
character special and directory files, respectively. The
second character of the mode 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 3-digit octal
number giving the owner, group, and other read, write, exe-
cute 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 of the specif-
ication may be a path name from which the contents and size
are copied. If the file is a block or character special
file, two decimal numbers follow which give the major and
minor device numbers. If the file is a directory, mkfs
makes the entries . and .. and then reads a list of names
and (recursively) file specifications for the entries in the
directory. As noted above, the scan is terminated with the
token $.
The gap blocks/cyl argument in both forms of the command
specifies the rotational gap and the number of
blocks/cylinder.
FILES
/etc/vtoc/*
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MKFS(1M) INTERACTIVE UNIX System MKFS(1M)
SEE ALSO
chmod(1).
dir(4), fs(4) in the INTERACTIVE SDS Guide and Programmer's
Reference Manual.
BUGS
With a prototype file, it is not possible to copy in a file
larger than 64K bytes, nor is there a way to specify links.
The maximum number of inodes configurable is 65500.
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