I've got 4 identical 1 TB drives and would like to use them in a software RAID configuration on my home server. I'm running Debian Linux using 'mdadm' utility to manage the software RAID. I don't know how much I've read is fact or dated or even false so I decided I would ask here to get help from people who know more about this than I do. This is essentially just a file server machine to store all my data so being that I've got four identical SATA hard drives, I was thinking about doing RAID level 5. I guess I'll start here and ask if that is the recommended level of RAID. I think RAID level 5 will be fine for my general server usage. My second issue is partitioning the four individual drives to get maximum performance / space from them. Basically just asking here how would you or you recommend I partition the drives? I was thinking about doing three seperate partitions per drive:

/dev/sda1 = 4 GB (swap)
/dev/sda2 = 1 GB (/boot)
/dev/sda3 = 995 GB (/)

Now from that partition schema above, obviously all the types will be 'fd' for RAID and the partition for /boot is going to be bootable. My confusion is that I read Grub doesn't support booting from RAID 5 since Grub can't handle disk assembly. If /dev/sdx2 (sda2, sdb2, sdc2, sdd2) are partitioned for /boot (bootable), how would you guys configure this RAID to match up equally? I don't think I do a RAID level 1 on 4 identical partitions, right? Can anyone please help and tell me how I should configure these 4 identical drives to work on my system? How would you set this up?

you wouldn't raid the entire thing, just the partitions relevant to the mirror. So /boot is fine as a single partition on a single disk. You can copy the data statically to another if you wish of course. OR you can boot to a raid 1 mirror on 2 disks, as the underlying block device is the same as when it is part of a mirror.

Personally I'd advise against a RAID5 array. I don't like them. They seem to be a great way to get as much data crammed in without risking anything, but when they go wrong it's not nearly as clear what's going on with the array etc. I'd recommend two mirrors personally, with an LVM instance joining them together. To me that's very logically clear what's goign on, adn you have 2TB to play with.

Also this allows for uneven block sizes. you make one pair of disks the first pair, which also contains the OS in proper conventional paritions using up, say, 50gb in total, and then the *rest* of that pair and *all* of the 2nd pair can then be joined up with LVM as a 1.95TB /data partition. You do lose a TB here sure, but your data is safer and you can feel much clearer on how you go forwards with it.