mtools(5) MTOOLS mtools(5)
mtools.conf - mtools configuration files
This manual page describes the configuration files for mtools. They are called
`/etc/mtools.conf' and `~/.mtoolsrc'. If the environmental variable MTOOLSRC is set, its
contents is used as the filename for a third configuration file. These configuration files
describe the following items:
* Global configuration flags and variables
* Per drive flags and variables
Location of the configuration files
`/etc/mtools.conf' is the system-wide configuration file, and `~/.mtoolsrc' is the user's
private configuration file.
On some systems, the system-wide configuration file is called `/etc/default/mtools.conf'
General configuration file syntax
The configuration files is made up of sections. Each section starts with a keyword identi-
fying the section followed by a colon. Then follow variable assignments and flags. Vari-
able assignments take the following form:
Flags are lone keywords without an equal sign and value following them. A section either
ends at the end of the file or where the next section begins.
Lines starting with a hash (#) are comments. Newline characters are equivalent to white-
space (except where ending a comment). The configuration file is case insensitive, except
for item enclosed in quotes (such as filenames).
For most platforms, mtools contains reasonable compiled-in defaults for physical floppy
drives. Thus, you usually don't need to bother with the configuration file, if all you
want to do with mtools is to access your floppy drives. On the other hand, the configura-
tion file is needed if you also want to use mtools to access your hard disk partitions and
DOSEMU image files.
Global flags may be set to 1 or to 0.
The following global flags are recognized:
If this is set to 1, mtools skips most of its sanity checks. This is needed to read
some Atari disks which have been made with the earlier ROMs, and which would not be
If this is set to 1, mtools skips the fat size checks. Some disks have a bigger FAT
than they really need to. These are rejected if this option is not set.
If this is set to 1, mtools displays all-upper-case short filenames as lowercase.
This has been done to allow a behavior which is consistent with older versions of
mtools which didn't know about the case bits.
If this is set to 1, mtools won't generate VFAT entries for filenames which are
mixed-case, but otherwise legal dos filenames. This is useful when working with
DOS versions which can't grok VFAT long names, such as FreeDOS.
In a wide directory, prints the short name with a dot instead of spaces separating
the basename and the extension.
If this is set to one (default), generate numeric tails for all long names (~1).
If set to zero, only generate numeric tails if otherwise a clash would have hap-
If 1, uses the European notation for times (twenty four hour clock), else uses the
UK/US notation (am/pm)
Example: Inserting the following line into your configuration file instructs mtools to
skip the sanity checks:
Global variables may also be set via the environment:
Global string variables may be set to any value:
The format used for printing dates of files. By default, is dd-mm-yyyy.
Per drive flags and variables
Per drive flags and values may be described in a drive section. A drive section starts
with drive "driveletter" :
Then follow variable-value pairs and flags.
This is a sample drive description:
For each drive, you need to describe where its data is physically stored (image file,
physical device, partition, offset).
file The name of the file or device holding the disk image. This is mandatory. The file
name should be enclosed in quotes.
Tells mtools to treat the drive as a partitioned device, and to use the given par-
tition. Only primary partitions are accessible using this method, and they are num-
bered from 1 to 4. For logical partitions, use the more general offset variable.
The partition variable is intended for removable media such as Syquest disks, ZIP
drives, and magneto-optical disks. Although traditional DOS sees Syquest disks and
magneto-optical disks as `giant floppy disks' which are unpartitioned, OS/2 and
Windows NT treat them like hard disks, i.e. partitioned devices. The partition flag
is also useful DOSEMU hdimages. It is not recommended for hard disks for which
direct access to partitions is available through mounting.
Describes where in the file the MS-DOS file system starts. This is useful for logi-
cal partitions in DOSEMU hdimages, and for ATARI ram disks. By default, this is
zero, meaning that the file system starts right at the beginning of the device or
Disk Geometry Configuration
Geometry information describes the physical characteristics about the disk. Its has three
The geometry information is written into the boot sector of the newly made disk.
However, you may also describe the geometry information on the command line. See
section mformat, for details.
On some Unixes there are device nodes which only support one physical geometry. For
instance, you might need a different node to access a disk as high density or as
low density. The geometry is compared to the actual geometry stored on the boot
sector to make sure that this device node is able to correctly read the disk. If
the geometry doesn't match, this drive entry fails, and the next drive entry bear-
ing the same drive letter is tried. See section multiple descriptions, for more
details on supplying several descriptions for one drive letter.
If no geometry information is supplied in the configuration file, all disks are
accepted. On Linux (and on SPARC) there exist device nodes with configurable geome-
try (`/dev/fd0', `/dev/fd1' etc), and thus filtering is not needed (and ignored)
for disk drives. (Mtools still does do filtering on plain files (disk images) in
Linux: this is mainly intended for test purposes, as I don't have access to a Unix
which would actually need filtering).
If you do not need filtering, but want still a default geometry for mformatting,
you may switch off filtering using the mformat_only flag.
If you want filtering, you should supply the filter flag. If you supply a geome-
try, you must supply one of both flags.
On devices that support it (usually floppy devices), the geometry information is
also used to set the initial geometry. This initial geometry is applied while read-
ing the boot sector, which contains the real geometry. If no geometry information
is supplied in the configuration file, or if the mformat_only flag is supplied, no
initial configuration is done.
On Linux, initial geometry is not really needed, as the configurable devices are
able to auto-detect the disk type accurately enough (for most common formats) to
read the boot sector.
Wrong geometry information may lead to very bizarre errors. That's why I strongly recom-
mend that you add the mformat_only flag to your drive description, unless you really need
filtering or initial geometry.
The following geometry related variables are available:
tracks The number of cylinders. (cylinders is the preferred form, tracks is considered
heads The number of heads (sides).
The number of sectors per track.
Example: the following drive section describes a 1.44M drive:
cylinders=80 heads=2 sectors=18
The following shorthand geometry descriptions are available:
1.44m high density 3 1/2 disk. Equivalent to: fat_bits=12 cylinders=80 heads=2 sectors=18
1.2m high density 5 1/4 disk. Equivalent to: fat_bits=12 cylinders=80 heads=2 sectors=15
720k double density 3 1/2 disk. Equivalent to: fat_bits=12 cylinders=80 heads=2 sec-
360k double density 5 1/4 disk. Equivalent to: fat_bits=12 cylinders=40 heads=2 sec-
The shorthand format descriptions may be amended. For example, 360k sectors=8 describes a
320k disk and is equivalent to: fat_bits=12 cylinders=40 heads=2 sectors=8
Moreover, the following flags are available:
sync All i/o operations are done synchronously
The device or file is opened with the O_NDELAY flag. This is needed on some non-
The device or file is opened with the O_EXCL flag. On Linux, this ensures exclusive
access to the floppy drive. On most other architectures, and for plain files it has
no effect at all.
General Purpose Drive Variables
The following general purpose drive variables are available. Depending to their type,
these variables can be set to a string (precmd) or an integer (all others)
The number of FAT bits. This may be 12 or 16. This is very rarely needed, as it can
almost always be deduced from information in the boot sector. On the contrary,
describing the number of fat bits may actually be harmful if you get it wrong. You
should only use it if mtools gets the auto-detected number of fat bits wrong, or if
you want to mformat a disk with a weird number of fat bits.
Describes the DOS code page used for short filenames. This is a number between 1
and 999. By default, code page 850 is used. The reason for this is because this
code page contains most of the characters that are also available in ISO-Latin-1.
You may also specify a global code page for all drives by using the global
default_codepage parameter (outside of any drive description). This parameters
exists starting at version 4.0.0
On some variants of Solaris, it is necessary to call 'volcheck -v' before opening a
floppy device, in order for the system to notice that there is indeed a disk in the
drive. precmd="volcheck -v" in the drive clause establishes the desired behavior.
This parameter represents a default block size to be always used on this device.
All I/O is done with multiples of this block size, independently of the sector size
registered in the file system's boot sector. This is useful for character devices
whose sector size is not 512, such as for example CD-ROM drives on Solaris.
Only the file variable is mandatory. The other parameters may be left out. In that case a
default value or an auto-detected value is used.
General Purpose Drive Flags
A flag can either be set to 1 (enabled) or 0 (disabled). If the value is omitted, it is
enabled. For example, scsi is equivalent to scsi=1
Instruct mtools to not use locking on this drive. This is needed on systems with
buggy locking semantics. However, enabling this makes operation less safe in cases
where several users may access the same drive at the same time.
scsi When set to 1, this option tells mtools to use raw SCSI I/O instead of the standard
read/write calls to access the device. Currently, this is supported on HP-UX,
Solaris and SunOS. This is needed because on some architectures, such as SunOS or
Solaris, PC media can't be accessed using the read and write system calls, because
the OS expects them to contain a Sun specific "disk label".
As raw SCSI access always uses the whole device, you need to specify the "parti-
tion" flag in addition
On some architectures, such as Solaris, mtools needs root privileges to be able to
use the scsi option. Thus mtools should be installed setuid root on Solaris if you
want to access Zip/Jaz drives. Thus, if the scsi flag is given, privileged is
automatically implied, unless explicitly disabled by privileged=0
Mtools uses its root privileges to open the device, and to issue the actual SCSI
I/O calls. Moreover, root privileges are only used for drives described in a sys-
tem-wide configuration file such as `/etc/mtools.conf', and not for those described
in `~/.mtoolsrc' or `$MTOOLSRC'.
When set to 1, this instructs mtools to use its setuid and setgid privileges for
opening the given drive. This option is only valid for drives described in the
system-wide configuration files (such as `/etc/mtools.conf', not `~/.mtoolsrc' or
`$MTOOLSRC'). Obviously, this option is also a no op if mtools is not installed
setuid or setgid. This option is implied by 'scsi=1', but again only for drives
defined in system-wide configuration files. Privileged may also be set explicitly
to 0, in order to tell mtools not to use its privileges for a given drive even if
scsi=1 is set.
Mtools only needs to be installed setuid if you use the privileged or scsi drive
variables. If you do not use these options, mtools works perfectly well even when
not installed setuid root.
Instructs mtools to interpret the device name as a vold identifier rather than as a
filename. The vold identifier is translated into a real filename using the
media_findname() and media_oldaliases() functions of the volmgt library. This flag
is only available if you configured mtools with the --enable-new-vold option before
Consider the media as a word-swapped Atari disk.
If this is set to a non-zero value, mtools also tries to access this disk as an XDF
disk. XDF is a high capacity format used by OS/2. This is off by default. See sec-
tion XDF, for more details.
Tells mtools to use the geometry for this drive only for mformatting and not for
Tells mtools to use the geometry for this drive both for mformatting and filtering.
Tells mtools to connect to floppyd (see section floppyd).
Supplying multiple descriptions for a drive
It is possible to supply multiple descriptions for a drive. In that case, the descriptions
are tried in order until one is found that fits. Descriptions may fail for several rea-
1. because the geometry is not appropriate,
2. because there is no disk in the drive,
3. or because of other problems.
Multiple definitions are useful when using physical devices which are only able to support
one single disk geometry. Example:
drive a: file="/dev/fd0H1440" 1.44m
drive a: file="/dev/fd0H720" 720k
This instructs mtools to use /dev/fd0H1440 for 1.44m (high density) disks and /dev/fd0H720
for 720k (double density) disks. On Linux, this feature is not really needed, as the
/dev/fd0 device is able to handle any geometry.
You may also use multiple drive descriptions to access both of your physical drives
through one drive letter:
drive z: file="/dev/fd0"
drive z: file="/dev/fd1"
With this description, mdir z: accesses your first physical drive if it contains a disk.
If the first drive doesn't contain a disk, mtools checks the second drive.
When using multiple configuration files, drive descriptions in the files parsed last over-
ride descriptions for the same drive in earlier files. In order to avoid this, use the
drive+ or +drive keywords instead of drive. The first adds a description to the end of the
list (i.e. it will be tried last), and the first adds it to the start of the list.
Location of configuration files and parsing order
The configuration files are parsed in the following order:
1. compiled-in defaults
4. `$MTOOLSRC' (file pointed by the MTOOLSRC environmental variable)
Options described in the later files override those described in the earlier files. Drives
defined in earlier files persist if they are not overridden in the later files. For
instance, drives A and B may be defined in `/etc/mtools.conf' and drives C and D may be
defined in `~/.mtoolsrc' However, if `~/.mtoolsrc' also defines drive A, this new descrip-
tion would override the description of drive A in `/etc/mtools.conf' instead of adding to
it. If you want to add a new description to a drive already described in an earlier file,
you need to use either the +drive or drive+ keyword.
Backwards compatibility with old configuration file syntax
The syntax described herein is new for version mtools-3.0. The old line-oriented syntax is
still supported. Each line beginning with a single letter is considered to be a drive
description using the old syntax. Old style and new style drive sections may be mixed
within the same configuration file, in order to make upgrading easier. Support for the old
syntax will be phased out eventually, and in order to discourage its use, I purposefully
omit its description here.
MTOOLS 28Feb10 mtools(5)