Extended attributes. This mainly includes extensions to the traditional UNIX
security model, such as SELinux security labels, POSIX ACLs, and capabilities
labels.
+.IP \[bu]
+Files that are neither regular files, directories, nor symbolic links, such as
+device files and FIFOs. These will be excluded by default.
.PP
Notes: hard links and symbolic links are supported by the WIM format and
\fIare\fR stored. (Symbolic links are turned into "native" Windows symbolic
\fISOURCE\fR using ntfs-3g. You must specify the NTFS volume itself (and it
must be unmounted, and you must have permission to read from it).
.PP
-The NTFS volume capture mode attempts to capture as much data as
+The NTFS volume capture mode attempts to capture as much data and metadata as
possible, including:
.IP \[bu] 4
-All data streams of all files, including the unnamed data stream as well as all
-named data streams.
+All data streams of all unencrypted files, including the unnamed data stream as
+well as all named data streams.
.IP \[bu]
Reparse points, including symbolic links, junction points, and other reparse
points.
.IP \[bu]
All names of all files, including names in the Win32 namespace, DOS namespace,
Win32+DOS namespace, and POSIX namespace. This includes hard links.
+.PP
+However, the main limitations of this NTFS volume capture mode are:
+.IP \[bu] 4
+Encrypted files are excluded by default. Although ntfs-3g can read their data,
+they need to be stored in the WIM file in a special format that wimlib does not
+yet support (except on Windows, where wimlib can treat the data as opaque and
+hand it off to the appropriate API function).
+.IP \[bu]
+The sparse attribute on sparse files will be saved, but the data stored will be
+the full data of the file rather than the "sparse" data. (The data is, however,
+subject to the WIM format's compression.)
.SH DIRECTORY CAPTURE (WINDOWS)
On Windows, \fB@IMAGEX_PROGNAME@ capture\fR and \fB@IMAGEX_PROGNAME@ append\fR
natively support Windows-specific and NTFS-specific data. They therefore act
default for \fB@IMAGEX_PROGNAME@ capture\fR, except when writing to standard
output (\fIWIMFILE\fR specified as "-"), and also for \fB@IMAGEX_PROGNAME@
append\fR, except when appending to a WIM that is already pipable.
+.TP
+\fB--update-of\fR=[\fIWIMFILE\fR]:\fIIMAGE\fR
+Declares that the image being captured from \fISOURCE\fR is mostly the same as
+the existing image \fIIMAGE\fR in \fIWIMFILE\fR, but captured at a later point
+in time, possibly with some modifications in the intervening time. This is
+designed to be used in incremental backups of the same filesystem or directory
+tree. \fIIMAGE\fR can be a 1-based index or name of an existing image in
+\fIWIMFILE\fR. It can also be a negative integer to index backwards into the
+images (e.g. -1 means the last existing image).
+.IP ""
+When this option is provided, the capture or append of the new image will be
+optimized by not reading files that, based on metadata such as timestamps,
+appear not to have been modified since they were archived in the existing
+\fIIMAGE\fR. Barring manipulation of timestamps, this option only affects
+performance and does not change the resulting WIM file.
+.IP ""
+As shown, the full syntax for the argument to this option is to specify the WIM
+file, a colon, and the image; for example, "--update-of mywim.wim:1".
+However, the WIM file may be omitted, in which case it will default to the WIM
+file being appended to for append operations, or the WIM file from which a delta
+is being taken (with \fB--delta-from\fR, if specified) for capture operations.
+.TP
+\fB--delta-from\fR=\fIWIMFILE\fR
+For \fB@IMAGEX_PROGNAME@ capture\fR only: capture the new WIM as a "delta" from
+\fIWIMFILE\fR. Any streams that would ordinarily need to be archived in the new
+WIM are omitted if they are already present in the \fIWIMFILE\fR on which the
+delta is being based. The new WIM will still contain a full copy of the image
+metadata, but this is typically only a small fraction of a WIM's total size.
+.IP ""
+To operate on the resulting delta WIM using other commands such as
+\fB@IMAGEX_PROGNAME@ apply\fR, you must specify the delta WIM as the WIM file to
+operate on, but also reference the base WIM using the \fB--ref\fR option.
+Beware: to retain the proper functioning of the delta WIM, you can only add, not
+delete, files and images to the base WIM following the capture of a delta from
+it.
+.IP ""
+\fB--delta-from\fR may be combined with \fB--update-of\fR to increase the
+speed of capturing a delta WIM.
+.IP ""
+As an example, consider the following backup and restore sequence:
+.IP ""
+.RS
+.nf
+(initial backup)
+
+$ wimcapture /some/directory bkup-base.wim
+
+(some days later, create second backup as delta from first)
+
+$ wimcapture /some/directory bkup-2013-08-20.dwm \\
+ --update-of=winbkup.wim:-1 --delta-from=winbkup.wim
+
+(restoring the second backup)
+
+$ wimapply bkup-2013-08-20.dwm --ref=bkup-base.wim 1 \\
+ /some/directory
+.RE
+.fi
+.IP ""
+However, note that as an alternative to the above sequence that used a delta
+WIM, the second backup could have simply been appended to the WIM as new image
+using \fB@IMAGEX_PROGNAME@ append\fR. Delta WIMs should be used only if it's
+desired to base the backups or images on a separate, large file that is rarely
+modified.
+.IP ""
+Note: unlike "pipable" WIMs (created with the \fB--pipable\fR option), "delta"
+WIMs (created with the \fB--delta-from\fR option) are compatible with
+Microsoft's software. You can use the /ref option of imagex.exe to reference
+the base WIM, similar to above.
+.IP ""
+Additional note: \fB@IMAGEX_PROGNAME@\fR is generalized enough that you can in
+fact combine \fB--pipable\fR and \fB--delta-from\fR to create pipable delta
+WIMs. In such cases, the base WIM must be captured as pipable as well as the
+delta WIM, and when applying an image, the base WIM must be sent over the pipe
+after the delta WIM.
.SH NOTES
\fB@IMAGEX_PROGNAME@ append\fR does not support appending an image to a split WIM.
.PP
git://wimlib.net / wimlib / blobdiff