Hi there. I am looking into setting up a file server on Slackware using an old 350MHz machine I have. I also have a Ultra ATA IDE Controller Card which supports RAID functions. I have read up on the RAID functions (0, 1, 0+1) but still have a couple of questions. At one point, I read that to the OS, a RAID setup will look like one big drive. Two set of questions. 1) Say I setup the RAID with two hard drives, an 80GB and a 120GB and use RAID function 0. Then the OS would see 200GB, correct? What if I used function 1, the mirror function? Would the OS only see hard drive connected to the primary connector on the controller card being that one is a mirror image of the other (in my example, the 80GB)? When using the mirror image function, should I use the same size drives? 2)I was planning on putting a total of three hard drives in the system. Two on the RAID controller and one to store the OS. Is this ok or does it defeat the propose of a RAID setup if using the mirror function being the mirror images would not include the OS? Sorry for the multiple questions: just trying to gain a good understanding of RAIDs. Thanks in advance.

Ideally, a RAID setup should include 2 drives of the same size because a RAID configuration will set up using the smallest capacity drive as its base. If you use a 80mb and 120mb drive in a stripe configuration (RAID 0), the operating system will see one 160mb drive. The 40mb remaining on the 120mb drive will not be available. Using the same 2 drives in a RAID 1 configuration will show up as a single 80mb drive. A third drive can be used only with a RAID 1 configuration. However using it as a back-up operating system is somewhat redundant since you already have 2 drives which mirror each other and either can boot the system. The third drive would, in my opinion, be put to better use as storage for music, video, pictures, etc. John 110