8 Replies Latest reply on Aug 10, 2011 3:31 PM by wonderspark

    Power-up sequence for RAID array

    wonderspark Level 1

      Hi, fellas ~


      In just a couple more days, I'll have received all the components for my new RAID. System breakdown:

      2009 Mac Pro (980W power supply inside), 3.33GHz quad core, Areca 1880ix-12, 16GB RAM, ATI 5870 or GTX 285 (depending on what I swap in, one at at time)

      30" Apple Cinema HD Display monitor (max 150W)

      22" Dell G2210 monitor (max 22W)

      Sans Digital TR8X w/ (6) WD2003FYYS 2TB RE4 HDDs (300W power supply inside), with two hot-spares installed. (8 total disks in box)

      APC Smart-UPS 1500 (SUA1500), rated 980W

      APC Back-UPS RS 1500, rated 865W

      (2) external HDDs for backups

      Voyager Q SATA drive dock (for bare drive backups and clones)


      I list all this because I'm wondering about the possible need / best practices for boot up sequence to avoid issues with the power provided by my two UPS units. In the RAID3 rebuild times thread, it was mentioned that one needs a massive UPS to handle a computer with a RAID, so I'm hoping to confirm my system is properly powered. Normally, I power up all drives prior to powering up the computer itself, and since this 8-bay RAID tower is only using a 300W power supply, it seems either one of the UPS units I have would be fine for that. I plan to use the smaller 865W UPS for the RAID and the 22" monitor. The Mac Pro has a 980W power supply, but I never see the UPS go beyond 25% during power-up. I plan to use the larger 980W Smart-UPS for the Mac Pro and the 30" ACD monitor.

      During heavy use, each will be powering:


      Smart-UPS (980W)

      263W = Mac Pro at full CPU load, perhaps higher during boot-up?

      150W = 30" ACD max brightness


      413 watts


      Back-UPS (865W)

      300W = RAID tower (not sure that it would ever hit that load)

      22W = 22" Dell monitor


      322 watts


      The other external drives I can just distribute on each of the UPS units with negligible effect, I believe.


      Does anyone see any problem with this arrangement? As it currently stands without the RAID, I've been through dozens of full power outages, nearby lightning strikes causing temporary outages from one to ten seconds, and other random light-flickering events without a single issue so far. It seems robust, but I turn to you all for more knowledge.



        • 1. Re: Power-up sequence for RAID array
          JEShort01 Level 4



          I have a couple of the SUA1500 units and they are awesome. The RS 1500 is a much lesser quality unit.


          I would suggest running everything but the monitor off the SUA1500, and the monitor on the RS 1500.


          The SUA1500 is quite capable of that load (mines seen higher w/o any glitches) and having all drives, controller, etc. on one common ground plane is much safer if you were to ever have a lightning stroke close by. Set your ARECA to use a 1 second delay for sequenced drive startup, or you could play with less (I think mine is 0.4 secs now). Then, you will never need a full current inrush of  "startup" power for your drives (even if the Sans Digital tower is running all of the time.



          • 2. Re: Power-up sequence for RAID array
            wonderspark Level 1

            First test done for RAID0 using five disks. I did this to approximate  what I might see in a six-disk RAID3. I used xbench 1.3, since I don't  know what else to use for disk speed testing.
            Disk Test = 1431.45

            Sequential = 907.07
            - Write 4K blocks =      808.51 MB/sec
            - Write 256K blocks =  1221.38 MB/sec
            - Read 4K =                106.30 MB/sec
            - Read 256K =            1158.14 MB/sec

            Random = 3392.92
            - Write 4K =                152.52 MB/sec
            - Write 256K =            1256.89 MB/sec
            - Read 4K =                101.80 MB/sec
            - Read 256K =            1155.77 MB/sec

            Seems pretty good to me. What do you all think? Should I use something else to test with?

            Next up, six-disk RAID3 tests!


            By the way, I secured the battery backup unit with a twist-tie to the GPU cables so that I would have an empty slot to run the internal / external (8087-8088) cable out to the tower. I have an eSATA card in the top slot, so I had to make room somehow, and wasn't keen to cut a hole in my case.

            • 3. Re: Power-up sequence for RAID array
              JEShort01 Level 4



              If your 4k sequential read number is a typo (looks way low compared with other numbers), then things seem to be in order and ready to configure the "3".


              If your 4k sequential read was reported correctly, then some more troubleshooting may be in order!



              1 person found this helpful
              • 4. Re: Power-up sequence for RAID array
                wonderspark Level 1

                Not a typo. I was thinking it made sense since I set the block size to 128K, but I'm new to this so obviously I don't know jack, hahaha.


                It's been building the RAID3 since a little after midnight last night, and now at 10:38am the initialization is at 25%. Here again, I thought that might be normal since the BBU was charging during that time as well. It's now 100% charged, and it seems to be initializing faster now, but who knows.


                I read that thread about getting a 1200W UPS, and it seems like the Areca cards are taking longer than people expected. I did change up what's plugged into what, and I only have the Mac Pro and RAID tower plugged into the 980W UPS (SUA1500), and the monitors and external drives plugged into the 865W UPS (Back-UPS RS 1500). The load lights on the big UPS show only one of five lit up, which means 20% or less if I'm not mistaken. Occasionally, a second of five will light up for a half-second, then go out. On the smaller UPS with the two monitors running, it indicates 7% load. I'm pretty sure that means my UPS units are NOT overloaded or starving for power. I think something else is causing the long initialization time. All I can think of is that the BBU is still in its first 24 hours, and my rebuild priority is set to low.


                I'm not too worried yet, since I have the weekend to get it all right.


                I did only test five of the WD2003FYYS drives in RAID0, because the other three were already in use internally in the Mac Pro for a few months now. They're all eight identical model drives as noted above, but from three different purchases from two vendors... Provantage and Amazon. I set the drives as follows:

                Enclosure 1

                - Slots 1, 2 and 3 = RAID3

                - Slot 4 = Hot Spare

                Enclosure 2

                - Slots 5, 6 and 7 = other half of RAID3 in enclosure 1

                - Slot 8 = Hot Spare


                My thinking here was that the six disk RAID3 would be better balanced by the use of both enclosures / cables to the Areca. I wonder if maybe it has to do with one half of the enclosure being connected to the external SFF-8088 port on the Areca, and the other being connected internally via the SFF-8087 port to SFF-8088 port cable.The documentation says the internal ports are preferred on the 1880ix-12. I might buy another internal-to-external cable and re-do it with that, skipping the external port completely.


                In the time it took to type this, I'm now at 25.8% initialized, so it's moving along. Thanks for your input!


                Edit: I also only have the standard 1GB of memory on the Areca, not 2GB or 4GB. The computer boots 2-3 times faster than it did with the old Apple RAID Card in there.


                Edit 2: It's actually external slots 1-4 instead of internal slots 1-8. One half of the set are on slots 1-4, and slots 5-12 are empty.

                • 5. Re: Power-up sequence for RAID array
                  wonderspark Level 1

                  It occurred to me that since this is an Areca 1880ix-12 (emphasis on the number 12 here), the extra four ports via the external SFF-8088 are sharing the internal ports somehow. I think that has to be related to why it's taking so long. I'm at 92.1% initialization completion after exactly 37 hours. I ordered another internal/external cable so I can avoid using the external port completely. I'm guessing that will mean I'll have to re-initialize this RAID3 set, but if I'm correct about the port sharing theory, it should only take the 6-12 hours I've heard so much about.


                  If anybody knows definitively about this issue, please feel free to let me know. Thanks!

                  • 6. Re: Power-up sequence for RAID array
                    wonderspark Level 1

                    If anyone cares, here are the results of disk speed tests on my three main volumes:

                    AJA tests: 1920x1080 10-bit, 16GB file write/read
                    - 640GB single internal drive (OS and programs) = 90MB/sec both write/read
                    - 3x1TB RAID 0 = 315MB/sec both write/read
                    - 6x2TB RAID 3 = 603MB/sec write, 550MB/sec read

                    • 7. Re: Power-up sequence for RAID array
                      Harm Millaard Level 7

                      You are correct on the 12 port version, you can have 12 internal disks, or 8 internal plus 4 external in the same array.

                      • 8. Re: Power-up sequence for RAID array
                        wonderspark Level 1

                        Update with two internal cables vs. one internal, one external:

                        AJA test @ 1920x1080 10-bit:

                        - 6x2TB RAID 3 = 625MB/sec write, 551MB/sec read

                        So, slight improvement, but probably just coincidence, not actually faster.