mkfs(1M) MISC. REFERENCE MANUAL PAGES mkfs(1M)
NAME
mkfs (s5) - construct an s5 file system
SYNOPSIS
mkfs [-F s5] [generic_options] special
mkfs [-F s5] [generic_options] [-b block_size] special
blocks[:i-nodes] [gap blocks/cyl]
mkfs [-F s5] [generic_options] [-b block_size] special proto
[gap blocks/cyl]
DESCRIPTION
generic_options are options supported by the generic mkfs
command.
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.
The options are:
-F s5 Specifies an s5-FSType.
-b blocksize
Specifies the logical block size for the file sys-
tem. 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.
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/c1d0s0
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
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mkfs(1M) MISC. REFERENCE MANUAL PAGES mkfs(1M)
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 direc-
tory. 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 specif-
ication 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
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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. The following values are recommended for
the devices available on the 3B2:
Gap Size Gap Size Gap Size
Device 512-byte FS 1K FS 2K FS Blks/Cyl
_____________________________________________________________________________
10M Hard Disk 8 10 12 72
30M Hard Disk 8 10 12 90
72M Hard Disk 8 10 12 162 (CDC Wren II)
72aM Hard Disk 8 10 12 144 (Micropolis)
72bM Hard Disk 8 10 12 162 (Priam)
72cM Hard Disk 8 10 12 198 (Fujitsu)
Floppy Disk 1 1 1 18
If the gap and blocks/cyl are not specified or are con-
sidered illegal values a default value of gap size 10 and
162 blocks/cyl is used.
NOTES
With a prototype file there is no way to specify hard links.
FILES
/etc/vtoc/*
SEE ALSO
generic mkfs(1M), dir(4), fs(4).
chmod(1) in the User's Reference Manual.
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