[CentOS] rsync backup to fileserver - mystery

Fri May 1 23:44:58 UTC 2015
Carl E. Hartung <carlh04426 at gmail.com>

On Fri, 1 May 2015 11:10:26 -0600
Frank Cox wrote:

> I have a daily cron job that runs the following command:
> rsync -av --delete /home/frankcox/ /mnt/fileserver/backup

Hi Frank,

I've seen this when using the -a flag where it turns out there are
discrepancies in ownerships (user:group, UID:GID) between the local
source and a remote target. The -a flag intends to preserve user:group
and timestamps, and despite the explicit 'archive mode' flag, it is
possible between different implementations of rsync and differences
between operating systems as well as differences between filesystems,
that some of those attributes aren't being fully respected and preserved
as the files are actually being written at the target. This can happen
silently, so the sender receives no indication that there's a problem.
In these cases, the next time rsync runs, it simply notes that there
are differences and copies what it perceives to be the "changed" files

Is there a specific rationale for using '-a' as opposed to the less
stringent '-r' (recursive)?