summaryrefslogtreecommitdiff
path: root/doc
diff options
context:
space:
mode:
Diffstat (limited to 'doc')
-rw-r--r--doc/coreutils.texi22
1 files changed, 19 insertions, 3 deletions
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 8e1b73d63..f4be2c2f0 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -7543,15 +7543,31 @@ Also, it is not portable to use @option{-R} to copy symbolic links
unless you also specify @option{-P}, as @acronym{POSIX} allows
implementations that dereference symbolic links by default.
-@item --reflink
-@opindex --reflink
+@item --reflink[=@var{when}]
+@opindex --reflink[=@var{when}]
+@cindex COW
+@cindex clone
+@cindex copy on write
Perform a lightweight, copy-on-write (COW) copy.
-Copying with this option can succeed only on some relatively new file systems.
+Copying with this option can succeed only on some file systems.
Once it has succeeded, beware that the source and destination files
share the same disk data blocks as long as they remain unmodified.
Thus, if a disk I/O error affects data blocks of one of the files,
the other suffers the exact same fate.
+The @var{when} value can be one of the following:
+
+@table @samp
+@item always
+The default behavior: if the copy-on-write operation is not supported
+then report the failure for each file and exit with a failure status.
+
+@item auto
+If the copy-on-write operation is not supported then fall back
+to the standard copy behaviour.
+@end table
+
+
@item --remove-destination
@opindex --remove-destination
Remove each existing destination file before attempting to open it