Here is my current hard drive setup:
Main Server (provides a file server, does other things too but they don't matter for RAID as they don't use much hard drive space):
* 1 500GB drive
Stores Gentoo Linux Operating System, file shares (they use the bulk of the space, of course) and a small amount of data for other programs.
* 1 80GB drive for storing Virtual Machines like Windows NT 4.0 Server, Windows Server 2003 and Windows Server 2008.
Windows NT 4.0 Server is not running most of the time, I just have it as I sometimes like to run older software just for the fun of it, it requires the lowest resources of all but doesn't have Active Directory/Group Policy at all (There is domain support and policy but it sucks) so it's fairly useless for actual usage.
Windows Server 2003 runs all the time and provides Active Directory/Group Policy and a couple other things.
Windows Server 2008 hardly ever runs because as it's based on the Windows Vista codebase, it barely runs at all on a Pentium 4 chipset with less then 1GB of RAM which is a good portion of the reason for buying a new system.
* 1 500GB backup drive
This drive holds back ups for nearly everything on the 500GB drive plus a few data file backups on other computers in the house
Media Center (records/downloads TV Shows and provides a file server for them, also a frontend but that doesn't matter for RAID)
* 1 80GB SATA drive
Holds the Gentoo Linux Operating System with mythtv and other components.
* 1 SATA drive that is 1TB in size
Holds the bulk of my TV Show recordings
* 1 drive that is 1TB in size
I got this drive about two months ago for backup purposes (The other 1TB too but doesn't matter) but have not gotten around to setting it up as I've been very busy.
* Various drives (1 250GB SATA, 1 200GB PATA, 1 300GB PATA)
This is for storage of TV Shows and DVD rips I would like to keep but wouldn't be a big deal to lose as I could get them again (it would just suck re-ripping things or waiting for them to record).
This actually was all I had with the addition of 2 250GB SATA drives that I replaced when the following occurred to me:
1. I needed more space.
2. Had some TV Shows that would be very hard to get again for various reasons.
3. Managing 6 small hard drives without any RAID at all is a major pain.
This is what I'm thinking for a new setup:
New Server and Media Center backend (Computer is built, just need to install Operating System and Configure)
* 300GB hard drive with Fedora Linux 10 and the Virtual Machines (should just be Windows Server 2008 but I can't say for sure until I start setting things up)
* 1TB backup drive with same function as above, possibly 1.5GB or more depending on what I decide
* 3TB RAID array with added 1TB for parity or 2TB RAID array with 2TB for parity depending on what I decide
For this RAID I will take the 2 drives of 1TB from the Media Center and the 2 drives of 1 TB I just got from Newegg.
* As for the 2 500GB SATA drives, the 4 80GB SATA drives (I have 3 listed above and one extra that isn't used), the 1 250GB SATA drive, 200GB and 300GB PATA drives, I have no idea what can use them for at the moment. I would like to use at least the 500GBs in either the RAID or as extra backup drives.