RAID Rookie Question for HTPC

[john.diaz1]

OK, I've got a pretty decent HTPC server and system. I've got A LOT of media and am filling it up fast. I want to expand to more storage and will be putting a nice sum of cash into large capacity HDDs, but before I do, I would like to get my feet wet in the RAID arena. I currently have NO backup or redundancy as my setup is really JBOD. I've lost one 3TB HDD a year ago that got me pretty upset, but I am so unsure of myself when it comes to RAID setups, I just keep playing with fire. I'm concerned my new setup will put myself at even more risk, so I want to start thinking about a RAID setup. Can I get some advice from you experts out there? I've included diagrams of my current setup as well as my desired setup. Is my desired setup feasible? Is it the "smart play"? Am I thinking of the right RAID setup? Is there a better one? What, if any, controller should I be looking at? Remember I am using it as storage for media (movies, TV shows, etc.) that is stremed across a home network as a NAS. Thanks a bunch in advance!

 

[Lutfij]

1| If I may be candid, you intend to have a RAID array but are we looking at your current HTPC to act as the node/hub? Meaning will it house all drives in question? If you do intend to have the drives in your existing system, then please list your system's full specs.

2| You may want to read through this excerpt,

RAID 5 consists of block-level striping with distributed parity. Unlike RAID 4, parity information is distributed among the drives, requiring all drives but one to be present to operate. Upon failure of a single drive, subsequent reads can be calculated from the distributed parity such that no data is lost. RAID 5 requires at least three disks.[11] RAID 5 implementations are susceptible to system failures because of trends regarding array rebuild time and the chance of drive failure during rebuild (see "Increasing rebuild time and failure probability" section, below).[22] Rebuilding an array requires reading all data from all disks, opening a chance for a second drive failure and the loss of the entire array. In August 2012, Dell posted an advisory against the use of RAID 5 in any configuration on Dell EqualLogic arrays and RAID 50 with "Class 2 7200 RPM drives of 1 TB and higher capacity" for business-critical data.[23]

from Wiki's RAID page.

3| I would suggest sticking with simple RAID 1 array but then again you will need to keep in mind that you're going to have to invest the exact same disk, make and model/capacity to ensure you've got an optimal RAID array up and running.

4| Have you thought about having JBOD and ensuring that all drives aren't over 1 partition?

 

[john.diaz1]

I have to apologize. I kind of misspoke a bit. The actual HTPC is not what is housing the RAID array. I have multiple client HTPCs throughout my home that read from the server, which I am hoping to implement the RAID setup onto. I currently have a large tower with PLENTY of HDD slots acting as the server. It houses all 11 HDDs currently with plenty real estate for more. I understand that isn't really the issue, but yes, I would still utilize the current tower/server to run the RAID array. However, RAID 1 simply isn't an option as the cost of the HDDs alone would be prohibitive. I would essentially lose half my storage space and I can't count that as an option. I currently have a JBOD and they are all just one partition. I am looking for at least some small level of redundancy.

 

[RealBeast]

Unless you have full backup, I would not trust RAID 5 with 30TB of data -- way too much risk of a URE (Unrecoverable Read Error) on a second drive during a rebuild for a lost disk that would cost you all the data. At that size I would go to RAID 6 even though it costs an extra disk.

The alternative, which is best, is a full backup on another RAID 5 array that is generally off to reduce your chance to lose everything.

There are several good brands of RAID controllers (including Areca, LSI and Adaptec). I use a lot of Adaptec and currently have a 6805 and 8805 on my home storage arrays. If you go this way with whatever brand it is usually cheapest to buy a kit if available (the card and two breakout cables SFF-8643 to 4 x SATA). You also need to have a PCIe x8 slot, so in a consumer motherboard an x16 slot that runs at x8, for these cards.

If you have slightly deeper pockets you can go with and Adaptec 71605 and run all your drives in two distinct arrays or one physical but two logical arrays to save you one disk (so RAID 6 but all data on a single physical array that shows up as two if you want that although you can just use folders). I would lean that direction if you already have all those 10TB HDDs. And I would *strongly* suggest that you insure HDD/motherboard compatibility with the controller before buying anything. A little planning makes it go way more smoothly.