making backups automatically

Hi,

I'm looking for an rsync command with the following features:
- From specified directories copy new & changed files to destination.
- Do not synchronise deletions.

Which attributes are needed on the rsync command?

Purpose (for those interested)
I'm going to use this in my dual-bay NAS (D-LINK DNS-323).
This is an example of what I have running now:
rsync -aivx /mnt/HD_a2/FOTOS /mnt/HD_b2/BACKUP

This is the scripting and HOWTO of the backup system for this NAS.
http://wiki.dns323.info/howto:backup

 

Don't use the --delete switch. For more details, see

Code:

man rsync

 

Thanks. I just found something very explanatory:

http://www.cyberciti.biz/faq/use-rsync-to-backup-directory/

indeed you are correct:
Assuming that USB pen or external USB hard disk is mounted at /mnt/usbpen, enter the following command to backup (sync) new files and changes to existing files but don't remove files in backup directory:
$ rsync -au /home/tom /mnt/usbpen

To delete files in backup directory that no longer exist in directory being backed up, enter:
$ rsync -au --delete /home/tom /mnt/usbpen[/SIZE]