->Third (just in case we should jump to a Hardware-Raid solution): Are ->there any problems to install SuSE Prof. 9.0 on a Hardware-Raid-1 disk?
If you have a Promise, 3Ware or other supported RAID hardware, those can be setup/used during the install as well.
I currently have a server booting off a Promise FastTrak TX2000 but the driver is only available as a binary driver off the promise website. If do you get a Raid controller be careful as there still is no driver to support Suse 9.0 only 7.1 through 8.2. I believe this situation of needing binary drivers is quite common with raid controllers as many companies don't want to release the entire driver as open source (sometime due to legal obligations). One last point, this is really the wrong place for this discussion as it's not really related to security. Nick