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Sun Fire 880 and Sony SDX-700C

Discussion in 'Sun Hardware' started by Vikas Agnihotri, Sep 2, 2003.

  1. How do I use a Sony AIT-3 (SDX-700C) drive with my Sun Fire 880 server?

    I installed a Sun X6540A (PCI dual-channel single-ended Ultra SCSI HBA) and
    it is working fine, but I am getting really low speeds (around 3MB/sec).

    I am using the same drive on a Sun Enterprise 450 server using its fast
    wide SCSI onboard and I get really good speeds (around 17MB/sec).

    What kind of HBA should I use with the 880?

    Vikas Agnihotri, Sep 2, 2003
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  2. Vikas Agnihotri

    Thomas Insel Guest

    I would imagine that you would want the X6758A (Sun PCI Dual Ultra3
    SCSI HBA).

    You should also compare /kernel/drv/st.conf on both hosts. You would
    normally want configuration entries for your AIT-3 drives. Is it possible
    the 450 has these and the V880 doesn't?

    Thomas Insel, Sep 3, 2003
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  3. Right, thats what I thought, since the SCSI connector on the back of the
    AIT-3 drive has "LVD/SE" written on it! The X6540A is single-ended all
    right, but it is not LVD (does that make sense, all these different SCSI
    standards are driving me nuts!)

    But the fact that it gives good speeds on the onboard SCSI on my E450
    (fast wide 20MB/sec SCSI) makes me wonder. Is there something special about
    the 880 that I need to do?

    i.e. the E450 uses the 'fas' driver, while the 880's X6540A uses the 'glm'
    driver. Does this matter?
    I added the tape-config-list entries to st.conf as per Sony's
    recommendation and copied it everywhere. (I didnt reboot, I just
    'modunload' the 'st' module and did a 'mt -f /dev/rmt/0 status' to reload
    the module with the st.conf entries, is this all right?)

    I still think it has to do with the 'glm' driver vs. the 'fas' driver.

    Anyone else has experience with this?

    Vikas Agnihotri, Sep 3, 2003
  4. Vikas Agnihotri

    Thomas Insel Guest

    LVD devices can fall back to SE if necessary, with a
    performance penalty. Of course, the same thing will
    be happening on your 450.
    You don't have a choice -- the different chipsets on the
    different HBAs require different drivers.
    This is good enough, provided the modunload was sucessful.
    There are lots of other possible problems -- check cabling
    and termination. How are you testing speed? If you're writing
    data from a filesystem, you could be seeing the results of
    disk differences.

    Thomas Insel, Sep 4, 2003
  5. The problem was the terminator. I was using a terminator marked 'LVD/SE'
    because thats what the drive says. But, like you say, since my HBA is only
    SE (not LVD), everything probably falls back to SE and therefore needs a
    plain SCSI terminator.

    Anyway, I just replaced my terminator with a plain 68-pin SCSI terminator
    and everything is fine. I am getting speeds of around 23MB/sec.

    [I am using Joerg Schlling's 'star' utility (the -time switch) to write to
    the tape and measure my throughput]

    Vikas Agnihotri, Sep 4, 2003
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