WIMLIB
-This is wimlib version 1.0.0 (September 2012). wimlib can be used to read,
+This is wimlib version 1.0.4 (October 2012). wimlib can be used to read,
write, and mount files in the Windows Imaging Format (WIM files). These
files are normally created by using the `imagex.exe' utility on Windows,
-but this library provides a free implementetion of imagex for UNIX-based
+but this library provides a free implementation of imagex for UNIX-based
systems.
+ WIM FILES
+
+A Windows Imaging (WIM) file is an archive. Like some other archive formats
+such as ZIP, files in WIM archives may be compressed. WIM archives support two
+Microsoft-specific compression formats: LZX and XPRESS. Both are based on LZ77
+and Huffman encoding, and both are supported by wimlib.
+
+Unlike ZIP files, WIM files can contain multiple independent toplevel directory
+trees known as images. While each image has its own metadata describing a
+directory tree and file access modes, files are not duplicated for each image;
+instead, each file is included only once in the entire WIM. Microsoft did this
+so that in one WIM file, they could do things like have 5 different versions of
+Windows that are almost exactly the same.
+
+Microsoft provides documentation for the WIM file format, XPRESS compression
+format, and LZX compression format. The XPRESS documentation is acceptable, but
+the LZX documentation is not entirely correct, and the WIM documentation itself
+is very incomplete and is of unacceptable quality.
+
+A WIM file may be either stand-alone or split into multiple parts.
+
WINDOWS PE
A major use for this library is to create customized images of Windows PE, the
image of Windows PE that can be put on a CD or USB drive, or published on a
server for PXE booting. See the main page `doc/mkwinpeiso.1' for more details.
+ COMPRESSION RATIO
+
+wimlib can create XPRESS or LZX compressed WIM archives. As of wimlib v1.0.3,
+the XPRESS compression ratio is slightly better than that provided by
+Microsoft's software, while the LZX compression ratio is approaching that of
+Microsoft's software but is not quite there yet. Running time is as good as or
+better than Microsoft's software.
+
+The following tables compare the compression ratio and performance for creating
+a compressed Windows PE image (disk usage of about 524 MB, uncompressed WIM size
+361 MB):
+
+ Table 1. WIM size
+
+ XPRESS Compression LZX Compression
+ wimlib imagex (v1.0.2): 145,283,871 bytes 139,288,293 bytes
+ wimlib imagex (v1.0.3): 139,288,293 bytes 131,379,869 bytes
+ Microsoft imagex.exe: 140,406,981 bytes 127,249,176 bytes
+
+ Table 2. Time to create WIM
+
+ XPRESS Compression LZX Compression
+ wimlib imagex (v1.0.2): 18 sec 49 sec
+ wimlib imagex (v1.0.3): 19 sec 30 sec
+ Microsoft imagex.exe: 25 sec 89 sec
+
+
DEPENDENCIES
* libxml2
* libfuse
Unless configured with --without-fuse, wimlib requires a non-ancient
- version of libfuse to be installed. see above). Most GNU/Linux
- distributions already include this, but make sure you have the libfuse
- package installed (libfuse-dev if your distribution distributes header
- files separately). FUSE also requires a kernel module.
- If the kernel module is available it will automatically be loaded if you
- try to mount a WIM file. For more information see
- http://fuse.sourceforge.net/. FUSE is also available for FreeBSD.
+ version of libfuse to be installed. Most GNU/Linux distributions
+ already include this, but make sure you have the libfuse package
+ installed, and also libfuse-dev if your distribution distributes header
+ files separately. FUSE also requires a kernel module. If the kernel
+ module is available it will automatically be loaded if you try to mount
+ a WIM file. For more information see http://fuse.sourceforge.net/.
+ FUSE is also available for FreeBSD.
* libntfs-3g
Unless configured with --without-ntfs-3g, wimlib requires the library
- and headers for libntfs-3g to be installed. Currently, the version
- dated 2012-1-15 is required because I've cloned some of the code from
- the library.
+ and headers for libntfs-3g version 2011-4-12 or later to be installed.
+ Versions dated 2010-3-6 and earlier do not work because they are missing
+ the header xattrs.h (and the file xattrs.c, which contains functions we
+ need).
* cdrkit (optional)
* mtools (optional)
It has been tested on x86 (32-bit) GNU/Linux occasionally.
-I have tested a previous version of wimlib on FreeBSD and it worked, but this is
-not well tested, especially with the more recent versions of this software.
+wimlib may work on FreeBSD. However, this is not well tested. If you do not
+have libntfs-3g 2011-4-12 or later available, you must configure with
+--without-ntfs-3g. Also, GNU coreutils is needed to run the test suite. Before
+mounting a WIM you need to load the POSIX message queue module (run `kldload
+mqueuefs').
wimlib should work on big endian machines but it has not been tested.
The code in ntfs-apply.c and ntfs-capture.c uses the NTFS-3g library, which is a
library for reading and writing to NTFS filesystems (the filesystem used by
-recent versions of Windows). Additionally, the code in ntfs-3g-security.c is
-mostly copied from NTFS-3g, but I'm hoping to get rid of this file eventually.
-See http://www.tuxera.com/community/ntfs-3g-download/ for more information.
+recent versions of Windows). See
+http://www.tuxera.com/community/ntfs-3g-download/ for more information.
lzx-decomp.c, the code to decompress WIM file resources that are compressed
using LZX compression, is originally based on code from the cabextract project
http://technet.microsoft.com/en-us/library/cc749447(v=ws.10).aspx, so you can
see how it compares.
+ GNU/Linux equivalents of WIM format
+
+What's the equivalent way to capture the filesystem of a GNU/Linux operating
+system into an archive file? You have a few options:
+
+SquashFS:
+ SquashFS (http://squashfs.sourceforge.net/) provides a compressed,
+ read-only filesystem for Linux, and it's probably the closest equivalent
+ of the WIM format and better designed. Although you can't mount
+ SquashFS read-write, when wimlib does this for WIM files it's really an
+ illusion since the WIM isn't actually modified until the image is
+ unmounted. Multiple top-level images in SquashFS files are not
+ supported, although nothing stops you from just putting each image in a
+ separate directory.
+
+FSArchiver:
+ FSArchiver (http://www.fsarchiver.org/Main_Page) is not widely used, but
+ it appears to have some features quite similar to the WIM format.
+
+Tar:
+ The well-known tar format can usually capture a UNIX filesystem just
+ fine, and compressing the tar file produces a good compression ratio
+ (better than WIM, especially if using XZ compression), but there is no
+ support for random access, file deduplication, multiple images per
+ archive, or extended attributes.
+
+Zip:
+ Zip shares some features with WIM but is not designed to store entire
+ filesystems.
+
+7z:
+ The 7z format has some nice features but is unfortunately not designed
+ with UNIX in mind.
+
MORE INFORMATION
See the manual pages for `imagex', the manual pages for the subcommands of
LICENSE
As of version 1.0.0, wimlib is released under the GNU GPL version 3.0 or later.
-This includes the files in the `programs' directory.
+This includes the files in the `programs' directory as well as the files in the
+`src' directory.
+
+wimlib is independently developed and does not contain any code, data, or files
+copyrighted by Microsoft. It is not known to be affected by any patents.
DISCLAIMER
git://wimlib.net / wimlib / blobdiff