From f8a4983d246b9c5a06be8ced4754efac2eb83fda Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 27 Apr 2016 20:28:07 -0500 Subject: [PATCH] wimcapture.1: add note about --update-of being unreliable on Windows --- doc/man1/wimlib-imagex-capture.1 | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/doc/man1/wimlib-imagex-capture.1 b/doc/man1/wimlib-imagex-capture.1 index f0d90bd4..b0c5f337 100644 --- a/doc/man1/wimlib-imagex-capture.1 +++ b/doc/man1/wimlib-imagex-capture.1 @@ -502,7 +502,7 @@ 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 image. +performance and does not change the resulting WIM image (but see note below). .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, @@ -510,6 +510,21 @@ the WIM file and colon may be omitted, in which case the WIM file will default to the WIM file being appended to for append operations, or the WIM file from which a delta is being taken (only if \fB--delta-from\fR is specified exactly once) for capture operations. +.IP "" +Note: in the Windows version of wimlib, it has been observed that +\fB--update-of\fR mode is not completely reliable at detecting changes in file +contents, sometimes causing the old contents of a few files to be archived +rather than the current contents. The cause of this problem is that Windows +does not immediately update a file's last modification timestamp after every +write to that file. Unfortunately, there is no known way for applications like +wimlib to automatically work around this bug. Manual workarounds are possible; +theoretically, taking any action that causes the problematic files to be closed, +such as restarting applications or the computer itself, should cause the files' +last modification timestamps to be updated. Also note that wimlib compares file +sizes as well as timestamps in determining whether a file has changed, which +helps make the problem less likely to occur; and the problem does not occur on +other operating systems such as Linux which maintain files' last modification +timestamps correctly. .TP \fB--delta-from\fR=\fIWIMFILE\fR For \fBwimlib-imagex capture\fR only: capture the new WIM as a "delta" from -- 2.43.0