Finally have all the parts for my NAS: adaptec 5405 + 3xWD500ABPS + GA-P35-DSL3 + Celeron 440 + crucial 2x1gb pc6400 + 4xhotswap bay + Radeon7000. It's going to be acting as a NAS primarily. Possibly being setup with a VPN to a remote location for backup purposes.

1. I was wondering are there any benefits or disadvantages of loading my OS(server2k3,2k8, or xp pro 64bit) onto my raid drives? The other option would be to add a small 40gig hdd for the OS.
2. Suggestion for the OS? Im open to opinions. Try to keep it within the windows realm unless there is a linux version where i dont need to know code to accomplish things. Btw, all the hardware supports 64-bit.
3. I have many raid options, im thinking of either Raid 5, raid 5ee, or raid 6. I have a 4th 500 gig hard drive, that i can incorporate for the 5ee and 6 if need be.

I think thats it. Thanks in advance.

Well first off if you use a Windows OS this will be more of a file server than a NAS but that is probably OK with you. The OS to use really depends on the rest of your network. Is it peer to peer? Are there any other servers on the network? How many people will be sharing the data? Will there be many different levels of sharing amoung users and so on?

If its just you and family and all simple shares I would still use a Server OS if you have it. If not then XP would work.

I would not use RAID 5e because you can not sustain a 2 drive failure at the same time. You can survive a single drive failure but you must have rebuild before a second drive can fail. Plus the writes on the 5 series Adaptec are very fast and using RAID 6 will not be that bad for writes. If you are talking 4 drives and dont mind 2 drives of overhead you migth also consider RAID 10. It is faster than RAID 5 or 6 and can sustain 1 drive failure and even 2 drive failures if it is 1 drive from each RAID 1 nest. Of course if you lose both drives in a single RAID 1 nest your done.

I would use a boot drive and not run the OS on the data array.

Thanks for your advice.

well i went with raid 5 + 1 hot spare. I also used a 40 gig drive for the OS. Down the road I will upgrade to a bigger backplane and expand my raid.

I went with server 2003 R2. Setup about 5 folder shares for my local network.

I would like to sync two of my folder shares with remote PC's over the internet, but I am having trouble finding a good solution/method.