I will be setting up a hardware based RAID array on a new server and I have some questions regarding RAID level 10. Currently I am running hardware based RAID 5 on Windows 2000 server running MS SQL Server 2000. On my new server, I will be running Windows 2003 server/ MS SQL Server 2000. If I understand RAID 10 correctly, half your drives are striped like RAID 5 and the other half of the drives mirror the first half. I am buying 6 hot-swap drives. For simplicity, lets say they are 10GB each. So the RAID 10 50% rule gets me to 30GB total space. (3 HDs * 10GB). My question is: Being these 3 drives are striped, do I have to now subtract an additional drive capacity out like I do for RAID 5? So I would end up with a total usable drive space of 20GB? Also in the case of a drive failure, how does it work? Currently in my RAID 5 if a drive fails everything runs a little slower but continues to run. I hot-swap the bad drive and the array rebuilds over the new drive and everything is back to normal. So in RAID 10 will it just switch over to the mirrored half that does not have the problem? Can I hot-swap the drive and will it rebuild and be back to normal like I do in RAID 5? Does RAID 10 give me an extra level of protection because I have stripping and mirroring? We had a bad stripe on our boot sector on our RAID 5 setup and the server would not boot up after a restart. Would RAID 10 prevent that from being an issue in the future? Is the OS and all files mirrored? Would it "know" not to mirror the bad stripe across? So would my mirrored drive be intact and continue to function? A lot of questions I know. Just trying to determine if I should stick with RAID 5 or if there are any benefits (and what they are) of RAID 10. Thanks to anyone who can help to answer my questions.