I've been considering a long-term project to build a 3TB+ RAID array to store my Anime collection. As I have never built a RAID array and as it's going to be so expensive I need every bit of information I can get, especially opinions and comments from people who have built or are maintaining a similarily sized array.
Now to the facts:
- My target capacity is 3TB, for starters.
- I'm considering building a SATA array from day one, perhaps even waiting a bit for BTX motherboards and PCI Express RAID controllers to avoid the bottleneck of the PCI bus.
- I'm considering using 250GB drives and RAID-5 (no idea on how many drives per array, though).
- I'm going to use the array for backup purposes only, so I don't necessarily need high performance, but I do need some degree of fault tolerance. I want to minimize the probability of losing data without building an overly expensive array.
- Backing up the data to CD-R/DVD-R is not an option, that's why I need the array.
And now the questions:
1. Is it wise to build a SATA array? I know the prices on PATA disks and controllers are lower, but as this is going to be a long-term project (I will be adding a disk every 2 or 3 months) I think there's going to be enough time for SATA prices to drop to or below current PATA prices. I don't mind paying a bit more for SATA if it means it's going to be easier to route all the cables, etc.
2. Is RAID level 5 a good choice for my expected usage of the array? How many disks should I use per array? Using RAID-5 means you lose the equivalent to one disk of capacity per array (a loss of 25% on a 4-disk array, compared to 12.5% on an 8-disk array), but of course 8-port controllers are much more expensive than 4-port ones, and on 8 disk arrays it's much more likely than two drives fail at the same time (although I seriously hope it never happens). And I must also consider the expected number of PCI Express slots on the upcoming BTX motherboards, if I go for this bus. All prototypes I've seen have only two 1x PCI Express slots, which means I could have at most 2 physical arrays. Two 6-disk arrays at 250GB per disk add up to a total of 2.5TB, half a terabyte below my initial target capacity.
3. As I mentioned I'm planning to build the array progressively, adding one disk every few months. The whole process could take more than two years; is it possible that I will face problems trying to find the exact disk model say two years from now? are current SATA drive models going to stay with us for a long time? does it really matter that much that drives on an array are exactly the same brand and model?
4. Of course I won't be able to fit this many disks in my current midi-tower case. I have no idea what kind of cases (and power supplies) are good for arrays like this. I'd like the case to have at least hot-swapping capability and be prepared for extra drive cooling. Any suggestions on a relatively cheap case for this?
5. Just out of curiosity, what OS is everyone managing their RAID array on?
6. Any advice on which drives to use?
7. Any other comments or opinions? What kind of array are you using?
Thanks a lot for every bit of info you can supply