Noob questions about an HGST 4u60 JBOD

Discussion in 'Chassis and Enclosures' started by chills, Nov 4, 2019.

  1. chills

    chills New Member

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    Hello :)

    I have a total of 30 10tb wd red pros that have been hooked up directly to my server's motherboard with sas cards->sata cables, and sata piggyback power in two rosewill lsv4500 cases. There is no external jbod unit, just disks connecting directly to the host and consumer grade psu. For reference, theyre all hooked up to the host running linux, using zfs set up in two 12+3 raidz3 configs

    Connecting disks this way is of course, a nightmare waiting to happen and not scalable. I'm looking to buy a `4u60 g460-j-12` on ebay to house my drives and would love if someone could answer my absolute noob questions. I've searched these forums as well as gone through the unit's user manual, but so many seemingly simple things are still unknown to me.


    1. Does the unit work with general SATA drives? The user manual doesn't list WD Reds (or any consumer drive). Will this include the upcoming 14tb WD reds and even larger drives for the foreseeable future?

    2. Does this entire unit only have 12gbs of throughput f0r all 60 drives? If not, how much bandwidth can I expect to pull through it?

    3. Are there internal sas cards in this unit? If so, is it possible to change out the sas cards in the 4u60 to something of my choosing, like a dell LSI 9206-16e?

    4. Will I need to worry about noise or thermals of my drives? I've read the G2 is incredibly loud, but would the G1 be quiet enough for normal home use? I'm running all consumer hardware right now so my noise is hardly 40dba, hard drives never above 45 celcius

    5. Do I just install IT-mode sas cards in my nas's motherboard, and run cables directly to this unit and can see the drives in linux as if they were attached directly?

    6. The manual says that rows need to be filled with blanks if they are not full. Is a blank just a caddy with no drive? If so, I'll purchase a unit with all 60 caddies so I should be all good?

      For reference, here is the back of the unit pulled from an ebay listing , I see some listings have a rear side with 8 mini-sas ports instead, not sure whats going on there, but it makes me believe that the connections on the bottom can somehow be changed out, maybe sas cards too

      [​IMG]

      Any help would be much appreciated, hopefully this post can help others new to this too!
     
    #1
  2. ari2asem

    ari2asem Member

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    those ports are qfsp+ ports. no sas ports.
    that unit is gen1 (1st generation) unit. much better with noise than gen2.

    gen2 has 4 sas port (sff-8644).

    depending firmware version of gen1 it can accept any brand (seagate for exmple) hdd.
    i have one, gen1 accepting sata-600 of 10tb.

    when using sata hdd, you can use 1 cable to connect this unit to your desktop/nas. it will recognize your hdd's. no need for 2 cables when using sata hdd. 2 cables are needed for sas hdd.

    no internal sas cards in this unit. you can't change the internal hdd control with a model you want.

    and indeed, this is direct attached unit to your hba card inside your nas.

    blank fillers are needed for better airflow inside the case. but you can use hdd tray's, too
     
    #2
  3. i386

    i386 Well-Known Member

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    #3
  4. ari2asem

    ari2asem Member

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    qsfp = sff-8436
     
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  5. i386

    i386 Well-Known Member

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  6. ari2asem

    ari2asem Member

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    #6
  7. chills

    chills New Member

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    Thanks for the help everyone!


    So even though im connecting through an sff8644 to qsfp (which is a network protocol?) cable, my host unit will still see these disks are directly attached in the same way as if they were connected directly to my IT-mode sas card?

    If I use only a single cable, will I be able to address all 60 drives, or does each qsfp port correspond to 30 drives?
    If a single cable can address all 60, and I do end up plugging in two qsfp cables, will I double my effective bandwidth to the jbod?

    Throughput is something I'm still a bit concerned about, could you recommend me a sas card I can get that can sustain a 40gbps link to this thingpas? I see a lot of QSFP+ to 8644 cables claiming 6gb/s, is this number multiplied by 4 for the # of channels, or does the whole cable really only move 6gb/s?
     
    #7
  8. ari2asem

    ari2asem Member

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    qsfp+ (do not confuse with qsfp) has bandwidth of around 40gbps. so the cable is not the limitation. bottleneck is hba card with external sas (sff-8644 port) which is 12gbps per port.

    you can use 60 sata-600 hdd's with 1 cable and hba in it-mode. your host machine will see all those 60 hdd as they were directly connected inside the host machine.

    when you use sas hdd's you needs 2 cables, because sas is mostly dual port.

    but...when you connect 2 cables with sata-600 hdd's and want to get highest speed, then your hba needs to support port multiplexing (or trunking. i dont remember the rigth term for this).

    there are no sas (or hba) cards with 40gpbs ports.
    even sas-4 hasn't 40gbps per port (sas-4 is 24gbps per port). and there are yet no any prpduct in the market with sas-4 specifications.
     
    #8
  9. JaZz9

    JaZz9 New Member

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    @ari2asem

    Can you link to the firmware that you are running to get these to accept non hitachi drives?

    Also, I am looking for a few cables to connect to my sas3 lsi card. Any brands that you would recommend?
     
    #9
  10. ari2asem

    ari2asem Member

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    #10
  11. JaZz9

    JaZz9 New Member

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    Do you know the firmware version? I'll get a copy from Hitachi and post it here if I can.
     
    #11
  12. ari2asem

    ari2asem Member

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    i guess i have 0421 firmware
     
    #12
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