mkfs [-F s5] [generic_options] [-b block_size] special size[:i-nodes] [gap blocks/cyl]
mkfs [-F s5] [generic_options] [-b block_size] special proto [gap blocks/cyl]
mkfs constructs an s5 file system by writing on the special file using the values found in the remaining arguments of the command line. mkfs builds a file system with a root directory and a lost+found directory. mkfs expands the lost+found directory to be as large as possible, while still fitting in one disk block.
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 i-nodes 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. /dev/rdsk/0s0
2. 4872 110
3. d--777 3 1
4. usr d--777 3 1
5. sh ---755 3 1 /sbin/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. slnk l--777 2 2 /var/tmp
11. $
12. $
Line 1 in the example is the name of a file
to be copied 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 i-nodes in the file system.
Lines 3-10 tell mkfs about files and directories to be included in this file system.
Line 3 specifies the root directory.
Lines 4-6 and 8-10 specify other directories and files.
Line 10 specifies the symbolic link slnk set up in /usr and containing /var/tmp.
The ``$'' on line 7 tells mkfs to end the branch of the file system it is on, and continue from the next higher directory. The ``$'' on lines 11 and 12 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 -bcdl to specify regular, block special, character special, directory, and symbolic link 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, 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 of the specification may be a path name whence 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. If the gap and blocks/cyl are not specified or are considered illegal values a default value of gap size 10 and 162 blocks/cyl is used.
The maximum number of i-nodes configurable is 65500.