[Discuss] When you omit rsync '--update' option

[gaf at blu.org (Jerry Feldman)]

On 05/03/2012 02:16 AM, Rich Braun wrote:
> I suffered a data loss yesterday and can't think of any possible recovery
> mechanism.  Perhaps I haven't thought it through completely; at the very least
> I can warn others about the dangers of rsync...
>
> Hindsight:  *always* use the --update (or -u) option to rsync.  I made the
> faulty assumption that older data would not overwrite newer data, by default;
> nope.  You have to specify this option.  I can't fathom *why* it's not the
> default, but...nope.
When you use rsync on a file or directory it will *ALWAYS* overwrite the
files at the destination unless you specify update. Also there is a not
in the man page about copying between different file systems.
In general I prefer to use rsnapshot for my backups where rsync uses
--link-dest so the target directory will be initially empty, but if the
same file exists in the link directory tree, then rsync will do a hard
link.

-- 
Jerry Feldman <gaf at blu.org>
Boston Linux and Unix
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