looking for the right raid solution

[lorenzop]

I have most of my home network running on a quad core athlon, 8gb ram, and xen on centos 5.5. brazilfw router and trixbox run virtual and the samba file server runs on the host. I have the whole setup housed in a wooden box on wheels the size of a desk, monitor and keyboard ontop, and an ion air filter built into one side, door with window on other side. the server has an internal 500gb drive for the host and virtual disk drives for xen, then I have esata ports in the pci slots plugging into the motherboard, giving me 5 esata ports. I then have the bulk storage drives on a rack near the back of the server inside the big server cabinet. this works well and runs cool enough. gives me quick and easy access to the drives without pulling everything out. I use 3 foot esata to sata cables to plug right into hard drives from the back of the server, and runs on the server's power supply with another set of plugs. everything partitioned ext3.

my problem is, I'd like to set up some kind of raid. miss-matched drives would be good because I currently have a 1tb and a 2tb in use. what I would like is raid 5, for both performance and mirroring, but that's way over my budget. I have a few 1tb drives I can use, so I think I'd like to set up external usb drives to do backups, so I don't have to worry about raid mirroring. so I guess that leaves me with a need for miss-matched drives showing up as one, but reliably. I don't want to ever deal with restoring from many 1tb backup drives. so what are my options? whatever solution I find, I'd like to keep it under $150 budget. I'll probably also get a second 2tb drive to add to the raid.

I've tried a few linux distro's that set up a nas, but they don't run under xen. maybe a real light weight linux system running freenas or something? but I'd also like to keep power consumption as low as I can too. besides, the box is full, with the server, media center, 2 large switches, and whatever else. something that would be ideal for me is something like the drobo nas, but with esata inputs instead of usb.