RAID By The Numbers



Your Standard MAP5021 Dual-Bay Burly SCSI Enclosure.
Pictured with Granite External GD9861-LVD 18-inch Shorty Ultra2 Cable,
dual MAPHT2 Front-Mount Auxiliary Fans, and GD1636 Remote LED Indicator.
RAID by magician. Photo by Frank T.

Why Pay More for Less?

If you have a pair of hands, don't fear a screwdriver, and can struggle through the following tutorial, you too can enjoy the beastliest thruput known to mankind, and you can pay less for the privilege.

The Ingredients

1. Seagate Cheetah Ultra160, Ultra320 10k drives or Seagate Cheetah Ultra320 15k.3 drives.

2. Granite Digital Teflon or Thermal Plastic Olefin internal ribbon cabling.

3. Granite Digital External Teflon or LVD cables.

4. Your choice of Burly Enclosure.

5. Granite forced-perfect digital-active terminators.

6. SCSI boards (ATTO is the king here. UL4S for single channel and UL4D for Dual channel):
   
   • ATTO UL4S Ultra320 host card;

   • ATTO UL4D Ultra320 Dual Channel host card;

A RAID is Not Necessarily Right for Everyone

Do you really need a RAID like this? The Gurus feel that if you have to ask the question, you probably do not.

Most Macintosh users can simply install a single Miles2 and a single Cheetah, and relish the fastest SCSI performance currently available on any computer platform.

Performance phreaks on a budget can install a pair of Cheetahs internally, and save the expense of an enclosure, fan kits, cabling and terminators. This approach to RAID yields phenomenal performance, and is very cost-effective, assuming that you have room inside your Mac for a pair of matched drives. G5 owners will have to go external since the G5 supports only a pair of SATA drives internally.

Generally speaking, RAID, whether internal or external, are for those times when nothing else will do:

• Sustained throughput is essential to you: recording large DV files, maintaining audio performance, scratch for Final Cut Pro.
  

• You need no-nonsense, blistering Photoshop scratch space.
  

• You need faster rendering for complex 3D objects.
  

• You need the absolute fastest thruput possible to render special effects in Premiere, AfterEffects, Final Cut Pro, or some other digital video application.
  

• You need to lay down more audio tracks.
  

• You need to accelerate disk-intensive database operations.
  

• You need to soothe that compelling itch to be the first performance phreak on your block with a Mac so fast it blows your hair back.
  

The result:

Beaucoup bandwith, baby.


The Recipe

This page is very long, and contains in condensed form all the guidance you will probably need to build your RAID. Each item links to a separate page covering each step, with additional detail and more specific photographs. A good way to use this Roll Your Own RAID tutorial may be to open a second browser window, then drag the links from each step to the second window. That way, you can consult this page, and review the detailed guidance for each step as you proceed. You may also wish to print this page, and use it as a checklist, while you work.

Here's what you do:

1. Observe the backplane of the MAP 5021 dual-bay enclosure, or one of our other burly enclosures. Take this opportunity to clear your work area, and devise a system for yourself, so you don't misplace screws or other necessary components. It's best to work in a low-static environment, recognizing that most of us don't have static-free workbenches in our homes, or clean rooms (like some Gurus we know). We like to use the bumpy foam that comes in your hard drive box for sorting screws and small parts, or other foam packing material. It helps you keep screws and parts in groups, and you can sort them left-to-right, in the order you remove them. It's easier to remember which screws have to go in next, when you reverse the process and reassemble your enclosure.

2. Remove the screws on the backplane. Use a Phillips head number two, or whatever you have laying around. We like to get tools at Sears. They're cheap, and warranted for life.

3. Carefully lift the cover off the unit. Don't scratch it. You'll be looking at it for a few years.

4. Gently pop out the front bezel pieces (assuming you are installing MAPHT2 Auxiliary Fans, which are recommended when using those fast and subsequently hotter running Cheetahs or AtlasIV's . Even if you aren't installing fans, pop out the bezels anyway, so you have more room to work. You can always replace them later. They simply snap in and out.

5. Carefully insert the MAPHT2 Auxiliary Fans into the front of the enclosure. Line them up, and screw them in. Use four screws, so they'll be real sturdy and burly and handle hundreds of openings and closings and plenty of rough handling. We're not recommending that you mistreat your hardware--it's just nice to overbuild everything you do, in case there's a nuke strike or an earthquake or your RAID falls off the desk.

6. Return to the rear of the enclosure. Remove the screws holding the 50-pin Centronics external interface into the enclosure backplane. Save them. You will need them again.

7. Completely remove the external 50-pin Centronics interface and the internal SCSI ribbon cabling from the unit, and meticulously count and set your screws to one side. You will need them later.

8. Route all spare internal wires towards the outside of the enclosure to get them out of the way and make lots of elbow room inside. Rubber bands or plastic flex-ties work nicely. The way we like to work, we use rubber bands to keep stuff out of the way, and then when we're closing the enclosure, we use flex-ties to keep things neat, and to minimize crowding inside the enclosure. You want to keep the interior as clear as possible, to maximize air flow through the case. The better air flows, the cooler your drives. Your data will be safer.

9. Find your internal 68-pin cabling. You should be installing a cable assembly with an appropriate number of internal connectors, depending on how many drives you plan to support now or in the future, assuming a commensurate number of available drive bays. Mate up the external connector of your 68-pin cabling with the GD4197 50-pin Centronics to 68-pin MicroD Adapter Plate when installing 68-pin SCSI cabling.

10. Attach the GD4197 Adapter Plate to the external cable connector using the included barrel screws.

11. Find your screws from step 7 above, when you removed the 50-pin PVC cabling from the enclosure. Attach the complete internal 68-pin cable assembly to the rear ports in the enclosure backplane.

12. Double-check your barrel screws and make sure the assembled cable interfaces nicely with the enclosure backplane.

13. Test your connectors for fit by carefully attaching an external Granite cable. If necessary, adjust your connectors. Note that you will need to carefully line up the attachment screws in the cable connector with the barrel screws in the backplane. Don't over-tighten them--they are soft metal, and can get mushed.

14. Ensure your external Granite terminator interfaces correctly with your external cable connectors before continuing.

15. Find your gorgeous Cheetahs. Gently screw the brackets from the MAPHT2 Aux Fan kit to the sides of the hard drive.

16. Make any necessary adjustments to the drive controller board at this time. You may want to disable parity ensure termination power is enabled on one drive (only on longer chains), and enable drive spin-up (this is typically enabled as a default).

    Quick digression: Yes, you will need to consult the technical documentation included with your drive. If no technical pamphlet or other documents were included, utilize the appropriate link on our drive page to check the manufacturer's guidance for your drive. If you are utterly confused, email a Gurus Support Engineer with the type of drive, and what you are doing, and one of us will advise you on how to configure your jumpers.

    Unless you are a rocket scientist with infinite patience who has the time to puzzle out the cryptically color-coded addressing connectors that plug into the SCSI address selector on the enclosure backplane, set the SCSI address using the included drive jumpers. If you are hell-bent on using the SCSI ID selector, we'll share our secret method for puzzling it out below.

17. Admire your handiwork for a moment. (The Cheetah really is a thing of beauty.)

18. Attach the drive activity LED indicator wires from the front of the enclosure to the appropriate pins on the front of the hard drive. Keep in mind that you may need to switch these wires around if the drive activity LED does not work properly when you spin your new drives up for the very first time. The rule of thumb is to set the colored wire on the upper pin, and the black (ground) wire on the lower. Sometimes it's different, so be flexible!

19. Connect the internal 68-pin cable to the rear of the hard drive. Now is a good time to attach the SCSI addressing leads to the appropriate pins on the rear of the drive. The rule of thumb we follow with typical success is to place the black ground connector horizontally across the bottom row of pins, and the connector with colored wires across the top row of pins. We typically make sure the metal in the connectors is facing up, but at minimum, you should ensure that both connectors are oriented the same way--either up or down.

20. Gently set the drive and attached brackets down into the enclosure interior.

21. Align the drive brackets with the sides of the interior enclosure chassis. Screw them into position.

22. Repeat as needed for additional drives. Make sure you use at least four screws at each cardinal point to secure the drive brackets. One of the things that drives us crazy about enclosures assembled by sweaty shops is the lazy tendency to only use two or three screws to hold devices into place. We run into this all the time. This is one reason why we build all our own stuff: we know we're using the right screws, we know we're using enough of them, and we know the quality of everything else going into the enclosure. That's probably one reason why you are reading this tutorial, and building your own RAID, too. This unit you are building will be faster, and better-built, than anything you can buy off-the-shelf, and it will cost less.

23. Attach the completed RAID to your Mac, remember to install your external terminator, and apply power. (Do not yet close the unit. Don't be that confident.) Make sure your power LED lights up. As the drives go through their boot diagnostics, watch the drive indicator LED. If it flickers, congratulate yourself for connecting the LED leads correctly. If not, make a note of it so you can switch the LED wires later.

24. Open your drive formatting application, and ensure that it sees all installed drives at the correct SCSI addresses. Remember that your SCSI card will always come preset by the factory at ID7. Since you have 14 other addresses to use, you should probably leave it at ID7. Drives are typically preset by the manufacturer to ID0, or sometimes ID6. It doesn't really matter how you set your SCSI ID's, as long as you have a system, and can identify which drive is at which address. We sometimes write on the inside covers of our enclosures, or on the backplanes, which devices are at which ID's. It aids troubleshooting. If all drives and SCSI controllers are properly detected, format and stripe your drives. Apple OSX RAID, ATTO ExpressStripe, SoftRAID 3 all do a fine job building RAID0 and RAID1 arrays. We are always surprised at the robust reliability of OSX RAID while the exceptional reliability and performance of SoftRAID's products are legendary. Test the completed RAID volumes. In OSX this is harder to do than to say. Effective benching programs are yet to be written in our opinion. The main problem appears to be in OSX's extensive use of caching within the system. Benchtest applications have difficulty with deep system cache and get false reads. You can now exult in the gnarly performance of your new Cheetahs.

25. Shut down. If you need to swap LED leads, remove the drives as necessary and do so. Test your drives again, and ensure the LEDs flicker appropriately when the drives are accessed. If you need to reset your drive ID selector, simply flip them over, and retest. if your devices show up at the appropriate SCSI ID numbers, congratulate yourself, and get ready for a reward. If they do not, you might want to shoot us an email. Make sure you are using the correct pins!

26. If the drives are behaving appropriately, close up your new burly enclosure, declare victory, and crack a brewski. This would be a good time to run Quickbench, ATTO's ExpressStripe test or Disk Basher to benchtest, while you savor your reward and exult in the raw speed of your drives. Remember to email us and tell us how much you love your new RAID! (Likewise, if you ran into problems at some step, shoot us an email and let us know how we can help. Definitely let us know if you have suggestions for improving these pages!)

27. Congratulations! You are now an official geek with a very, very fast RAID! Depending on which RAID software and which Ultra320 SCSI boards you use, you can rest secure in knowing that you now own one of the fastest RAIDs available anywhere--and you built it!

The Gurus Certify
These Instructions Work