I want to mirror an existing 40GB data only drive using software Raid1 on my new CentOS 4 server. The existing drive is connected to a Promise Ultra 100 TX2 controller (non-raid). I have read about mdadm and understand how to create the Raid1 on /dev/mdxx devices. However I would like to know if the existing data on the orignal 40GB drive in the system will be destroyed when I create the raid with mdadm. Also do the 2 drives after being setup with mdadm have to be reformated? Both the 40GB drives are now formated with ext3. If not, will the added 40GB drive assigned to the Raid1 atomaticly sync to the original 40GB drive. If so, what do I need to do to assure this will happend automaticly? Your comments are appreciated, as this is my first time to setup a software Raid1. Lee __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com