it() The file's data will be in an inconsistent state during the transfer
and will be left that way if the transfer is interrupted or if an update
fails.
- it() A file that does not have write permissions cannot be updated.
+ it() A file that rsync cannot write to cannot be updated. While a super user
+ can update any file, a normal user needs to be granted write permission for
+ the open of the file for writing to be successful.
it() The efficiency of rsync's delta-transfer algorithm may be reduced if
some data in the destination file is overwritten before it can be copied to
a position later in the file. This does not apply if you use bf(--backup),
This option is useful for transferring large files with block-based changes
or appended data, and also on systems that are disk bound, not network
-bound.
+bound. It can also help keep a copy-on-write filesystem snapshot from
+diverging the entire contents of a file that only has minor changes.
The option implies bf(--partial) (since an interrupted transfer does not delete
the file), but conflicts with bf(--partial-dir) and bf(--delay-updates).