rsync feature needed: preserve atime

[Dave Dykstra]

On Tue, May 08, 2007 at 07:09:06PM -0400, Matt McCutchen wrote:
> On 5/8/07, Brent Thompson <brent at kanha.hpl.hp.com> wrote:
> >Often we need to preserve the information atime conveys, but I have found
> >no way to get rsync to preserve this, nor any hint it is being worked on.
> >It would be great if 'rsync -t' also set atime not just mtime -- or maybe a
> >new option is desired for atime.
> 
> The standard version of rsync does not support preserving atimes, but
> the rsync source distribution includes a patch "patches/atimes.diff"
> that adds an option --atimes to preserve atimes.  I recommend you
> compile your own copy of rsync including this patch (reply if you need
> help/instructions for this) and then use it with its --atimes option.


What does it really mean to preserve access times?  When rsync reads
a file to copy it, it will change the access time just because it is
reading it, so the backup should then have the correct access time,
the time the backup file was created.  Some tools have an option to
reset the access time of the file they copy, but in so doing the tools
update the inode change time of the input file which is generally more
important to users than access time.  It is not possible to preserve
both as a filesystem user like rsync.

- Dave