MKUDFFS
Section: Maintenance Commands (8)
Updated: udftools
Page Index
NAME
mkudffs --- create a UDF filesystem
SYNOPSIS
mkudffs [ options ] device [ blocks-count ]
DESCRIPTION
mkudffs is used to create a UDF filesystem on a device (usually a disk).
device is the special file corresponding to the device (e.g.
/dev/hdX) or file image.
blocks-count is the number of blocks on
the device. If omitted,
mkudffs automagically figures the filesystem
size. The order of options matters. Encoding option must be first and options to
override default settings implied by the media type or UDF revision should be
after the option they are overriding.
OPTIONS
- -h,--help
-
Display the usage and list of options.
- -l,--label= label
-
Specify the UDF label. UDF label is synonym for specifying both --lvid
and --vid options. If omitted, mkudffs label is LinuxUDF. (Option available since mkudffs 1.1)
- -u,--uuid= uuid
-
Specify the UDF uuid. It must be exactly 16 hexadecimal lowercase digits and is
used for first 16 characters of --fullvsid option. If omitted,
mkudffs uuid is generated from local time and a random number. (Option
available since mkudffs 1.1)
- -b,--blocksize= block-size
-
Specify the size of blocks in bytes. Valid block size for a UDF filesystem is
power of two in range from 512 to 32768 and must match a device
logical (sector) size. If omitted, mkudffs block size is set to device
logical block (sector) size. If logical block (sector) size is unknown (e.g. when creating disk image) then for --media-type=hd is used block
size 512 and for other media types 2048. (Prior to mkudffs 1.1
default value was always 2048 independently of --media-type)
- -m,--media-type= media-type
-
Specify the media type. Must be specified before --udfrev. Default
value is autodetected. When autodetection does not work (e.g. when creating
disk image) then hd value is assumed. Valid media types are:
-
- hd
-
HD (Hard Disk)
- worm
-
WORM (Write Once Read Many)
- mo
-
MO (Magneto Optical)
- cd
-
CD-ROM (CD Read-Only Memory)
- cdr
-
CD-R (CD Recordable)
- cdrw
-
CD-RW (CD Read-Write)
- dvd
-
DVD-ROM (DVD Read-Only Memory)
- dvdr
-
DVD-R (DVD Recordable)
- dvdrw
-
DVD-RW (DVD Read-Write)
- dvdram
-
DVD-RAM (DVD Random Access Memory)
- bdr
-
BD-R (Blu-ray Disc Recordable)
-
(Short option variant -m and values cd, dvdr, bdr are
available since mkudffs 2.0 and autodetection is supported since mkudffs 2.2)
- -r,--udfrev= udf-revision
-
Specify the UDF revision to use, either in hexadecimal BCD (e.g. 0x0201)
or decimal (e.g. 2.01) format. Valid revisions are 1.01, 1.02,
1.50, 2.00, 2.01, 2.50 and 2.60. If omitted,
mkudffs UDF revision is 2.01, except for Blu-ray Discs which is
2.50. UDF revisions higher then 2.01 are experimental. Option must
be specified after --media-type. (Values in decimal format and UDF
revisions higher then 2.01 are supported since mkudffs 2.0, UDF revision
1.01 is supported since mkudffs 2.1)
- -n,--no-write
-
Not really, do not write to device. Just simulate and display what would
happen with device. Useful for determining the calculated location of
different UDF blocks. (Option available since mkudffs 2.0)
- --new-file
-
Create a new image file specified by device with blocks-count and
fail if file already exists. If omitted, mkudffs creates a new image file
only in case it does not exist yet. (Option available since mkudffs 2.0)
- --lvid= logical-volume-identifier
-
Specify the Logical Volume Identifier. If omitted, mkudffs Logical
Volume Identifier is LinuxUDF. Most UDF implementations use this
identifier as a disk label.
- --vid= volume-identifier
-
Specify the Volume Identifier. If omitted, mkudffs Volume Identifier
is LinuxUDF.
- --vsid= volume-set-identifier
-
Specify the 17.-127. character of Volume Set Identifier. If omitted,
mkudffs Volume Set Identifier is LinuxUDF.
- --fsid= file-set-identifier
-
Specify the File Set Identifier. If omitted, mkudffs File Set
Identifier is LinuxUDF.
- --fullvsid= full-volume-set-identifier
-
Specify the full Volume Set Identifier. Overwrite previous --uuid
and --vsid options. (Option available since mkudffs 1.1)
- --uid= uid
-
Specify the uid of the root (/) directory. If omitted, mkudffs uid is
0. Special value -1 means invalid or not specified uid. (Option
available since mkudffs 1.1)
- --gid= gid
-
Specify the gid of the root (/) directory. If omitted, mkudffs gid is
0. Special value -1 means invalid or not specified gid. (Option
available since mkudffs 1.1)
- --mode= mode
-
Specify permissions in octal mode bits of the root (/) directory. If omitted,
mkudffs mode is 0755. (Option available since mkudffs 2.0)
- --read-only
-
This option specify that the whole UDF disk should be treated as read-only. It
sets SoftWriteProtect domain flag in Logical Volume Descriptor and
in File Set Descriptor. Plus for overwritable media types (hd,
dvdram, dvdrw) set UDF Access Type to read-only. (Option
available since mkudffs 2.2)
- --bootarea= fill
-
Specify how to fill UDF boot area which is the first 32kB of the disk and is not
used by UDF itself. Option mbr make sense only when running mkudffs
on whole disk, not on just one partition. Valid options are:
-
- preserve
-
preserve existing UDF boot area, do not touch it (default for media type
different from hd)
- erase
-
erase existing UDF boot area, fill it by zeros (default for hd media type
on partitions and on removable disks)
- mbr
-
put MBR table with one partition which starts at sector 0 (includes MBR itself)
and spans whole disk device, needed only for non-removable hard disks used on
Microsoft Windows systems (default for hd media type on non-removable hard
disk without partitions), see section WHOLE DISK VS PARTITION
-
(Option available since mkudffs 2.0)
- --strategy= strategy
-
Specify the allocation strategy to use. Valid strategies are 4 and
4096. If omitted, mkudffs strategy is based on the
--media-type.
- --spartable, --spartable= spartable-number
-
Enable usage Sparing Table. Optionally specify also the number of sparing
tables. Valid numbers are 1-4. When the spartable number is omitted
then two tables are written to the disc. If the option is omitted then usage of
Sparing Table depends on the media type. (Option prior to mkudffs 2.0 was
available only for cdrw media type)
- --sparspace= num-of-entires
-
Specify the number of entries in Sparing Table. If omitted, the default number
of entries is 1024, but depends on the media type. (Option available since
mkudffs 2.0)
- --packetlen= length
-
Packet length in a number of blocks used for alignment. All continuous UDF
structures would be aligned to packets. It specifies also the size of the
Sparing Space and packet length in Sparing Table. It should match the device
ECC/packet length. If omitted, default value for DVD discs is 16 blocks,
for CD/BD discs it is 32 blocks and otherwise 1 block. (Option prior
to mkudffs 2.1 was available only for cdrw and dvdrw media types)
- --vat
-
Enable usage of Virtual Allocation Table (VAT). If omitted, usage depends on
the media type. (Option available since mkudffs 2.0)
- --closed
-
Close disc with Virtual Allocation Table. AVDP is written also to the end of
the disc. By default, the disc with Virtual Allocation Table is not closed.
- --space= space
-
Specify the Space Set. Unallocated Space Set is used for media which
blocks may be allocated immediately. Freed Space Set is used for media
which blocks needs to be specially prepared/erased before allocation. In Space
Table is stored list of unallocated extents. In Space Bitmap is
stored bitmap of unallocated blocks. Not used for VAT.
-
- freedbitmap
-
Freed Bitmap
- freedtable
-
Freed Table
- unallocbitmap
-
Unallocated Bitmap (default)
- unalloctable
-
Unallocated Table
- --ad= ad
-
Specify the Allocation Descriptors of the root (/) directory.
-
- inicb
-
Allocation Descriptors in ICB (default)
- short
-
Short Allocation Descriptors
- long
-
Long Allocation Descriptors
- --noefe
-
Don't Use Extended File Entries for the root (/) directory. Affects only UDF
2.00 or higher. Must be specified after --udfrev.
- --locale
-
Treat identifier string options as strings encoded according to the current
locale settings (default). Must be specified as the first argument. (Option
available since mkudffs 2.0)
- --u8
-
Treat identifier string options as strings encoded in 8-bit OSTA Compressed
Unicode format without leading Compression ID byte, which is equivalent to
Latin1 (ISO-8859-1). Must be specified as first argument.
- --u16
-
Treat identifier string options as strings encoded in 16-bit OSTA Compressed
Unicode format without leading Compression ID byte, which is equivalent to
UTF-16BE. Note that it is not possible to include zero byte in command line
options, therefore any character which has at least one zero byte cannot be
supplied (this applies to all Latin1 characters). Must be specified as the
first argument.
- --utf8
-
Treat identifier string options as strings encoded in UTF-8. Must be specified
as the first argument. (Prior to mkudffs 2.0 this was default option)
COMPATIBILITY
OPERATING SYSTEMS SUPPORT
UDF filesystem is natively supported by large amount of operating systems. See
following compatibility table:
| Operating system | Maximum UDF revision for |
|
| Name | Version | read | write
|
|
| Linux | 2.3.17 - 2.4.5 | 2.00 | 2.00
|
| 2.4.6 - 2.6.25 | 2.01 | 2.01 |
| 2.6.26 (and new) | 2.50 | 2.01 |
|
| Windows | 98/Me | 1.02 | none
|
| 2000 | 1.50 | none |
| XP | 2.01 | none |
| Vista (and new) | 2.60 | 2.50 |
|
| Mac OS | 8.1 - 8.5 | 1.02 | none
|
| 8.6 - 9.2 | 1.50 | 1.50 |
|
| Mac OS X | 10.0 - 10.3 | 1.50 | 1.50
|
| 10.4 | 2.01 | 2.01 |
| 10.5 (and new) | 2.60 | 2.50 |
|
| FreeBSD | 5 (and new) | 1.50 | none
|
|
| NetBSD | 4.0 | 2.60 | none
|
| 5.0 (and new) | 2.60 | 2.60 |
|
| OpenBSD | 3.8 - 3.9 | 1.02 | none
|
| 4.0 - 4.6 | 1.50 |
| 4.7 (and new) | 2.60 |
|
| Solaris | 7 (and new) | 1.50 | 1.50
|
|
| AIX | 5.2 (and new) | 2.01 | 2.01
|
|
Note that Windows 98 and Windows Me can read UDF filesystem only from CD and DVD
optical discs, not from hard disks.
BLOCK SIZE
In most cases, operating systems are unable to mount UDF filesystem if UDF block
size differs from logical sector size of the device. Typically hard disks have
sector size 512 bytes and optical media 2048 bytes. Therefore UDF block size
must match the logical sector size of the device.
Linux kernel prior to version 2.6.30 used hardcoded UDF block size of 2048 bytes
independently of logical sector size, therefore it was not able to automatically
mount UDF filesystem if block size differed from 2048. Since 2.6.30 and prior to
4.11 Linux kernel used a logical sector size of the device as UDF block size,
plus it tried fallback to 2048. Since 4.11 it uses logical sector size and
fallbacks to any valid block size between logical sector size and 4096. Therefore since version 2.6.30 Linux kernel can automatically mount UDF
filesystems correctly if UDF block size matches device logical sector size and
since version 4.11 can automatically also mount devices which sector size does
not match UDF block size. In any case and also for Linux kernel prior to version
2.6.30, different UDF block size (which is not autodetected) can be manually
specified via bs=blocksize mount parameter.
WHOLE DISK VS PARTITION
UDF filesystem is supposed to be formatted on the whole media and not to the
partitioned hard disk. Mac OS X systems enforce this rule and reject to
automatically mount UDF filesystem unless it is formatted on the whole
unpartitioned hard disk. Possible partition table (e.g. MBR or GPT) on disk with
valid UDF filesystem is ignored. On the other hand, Microsoft Windows systems
are unable to detect non-removable hard disks without MBR or GPT partition
table. Removable disks do not have this restriction. A consequence is that
non-removable hard disks formatted to UDF by Windows Vista+ are not recognized
by Mac OS X systems and vice-versa. Note that manual mount of UDF partition on
partitioned hard disk on Mac OS X system is possible and working (e.g. by
running commands:
mkdir /Volumes/DriveName && mount_udf
/dev/disk1s1 /Volumes/DriveName). But there is no known way to mount an
unpartitioned non-removable disk on Windows system.
Thanks to reserved and unused UDF boot area (first 32kB of UDF filesystem) it is
possible to deal with this problem, by putting MBR on such non-removable hard
disk just for compatibility reasons with Windows. Such MBR table would contain
one partition which starts at sector 0 (includes MBR itself) and spans whole
disk device. So the whole disk device and also the first partition on disk
points to same sectors. Therefore UDF filesystem can be mounted either from
whole disk device (needed for Mac OS X systems) or from first partition (needed
for Microsoft Windows systems).
Linux kernel ignores MBR table if contains partition which starts at sector 0. Normally Linux kernel can detect and mount UDF filesystem either on a partition
or on whole disk device. It does not have any restrictions.
mkudffs option --bootarea=mbr put such MBR table for
compatibility with Microsoft Windows systems into disk when formatting.
LINUX LABEL BUGS
In most cases
Logical Volume Identifier is used as UDF label. But Linux
libblkid prior to version 2.26 used
Volume Identifier. Therefore
mkudffs --label for compatibility reasons set both
Logical
Volume Identifier and
Volume Identifier.
Linux libblkid prior to version 2.30 incorrectly processed non-ASCII identifier
strings encoded in 8-bit OSTA Compressed Unicode format. Therefore mkudffs
since version 2.0 for compatibility reasons tries to encode a non-ASCII
identifier strings in 16-bit OSTA Compressed Unicode format and then fallbacks
to 8-bit format.
For more information about UDF Label and UUID see udflabel(8) section
UDF LABEL AND UUID.
EXIT STATUS
mkudffs returns 0 if successful, non-zero if there are problems.
LIMITATIONS
mkudffs cannot create UDF 2.50 Metadata partition, therefore it does not
support UDF revisions higher than 2.01 for non Write Once media yet. So there is
no support for Blu-ray discs which needs UDF 2.50 (except for Blu-ray Disc
Recordable which does not require Metadata partition).
mkudffs prior to version 2.2 was unable to process Unicode strings with
code points above U+FFFF. When option --utf8 was specified then input
strings were limited to 3-byte UTF-8 sequences and when option --u16
was specified then input strings were limited just to UCS-2BE strings (subset
of UTF-16BE).
BUGS
mkudffs prior to version 1.1 was unable to process non-ASCII characters
from identifier strings in
--utf8 mode,
--vsid option was
completely broken and
--blocksize must have been manually specified for
hard disks as default value was hardcoded for optical disks.
mkudffs prior
to version 2.0 generated broken and unreadable
cdr disc images.
AUTHOR
Ben Fennema
Pali Rohár <pali.rohar@gmail.com>
AVAILABILITY
mkudffs is part of the udftools package and is available from
https://github.com/pali/udftools/.
SEE ALSO
pktsetup(8),
udflabel(8),
cdrwtool(1),
udfinfo(1),
wrudf(1)