External eSATA drive spontaneously disconnects

Discussion in 'Mac Pro' started by fourfa, Oct 1, 2009.

  1. fourfa macrumors newbie

    Joined:
    Oct 1, 2009
    #1
    Machine is an early 2008 Mac Pro. I'm connecting two external SATA desktop hard drives via eSATA (NewerTech Voyager S2 enclosures) and a Newer Technology eSATA Extender Cable (connected to the 5th and 6th internal SATA headers). One of the drives is used as a Time Machine backup disk. This TM disk has been periodically disconnecting and generating warning messages about improper ejection. It reconnects with a restart, but usually will disconnect again within a day. I swapped the drives in the docks, so each was connected via the other dock, cable, and internal header. The same problem persists - the TM disk disconnects periodically despite having switched docks.

    Seems like it might be a disk problem. Any thoughts? Any way to test for detectable problems?
     
  2. fourfa thread starter macrumors newbie

    Joined:
    Oct 1, 2009
  3. rtrt, Oct 2, 2009
    Last edited: Aug 13, 2011
  4. fourfa thread starter macrumors newbie

    Joined:
    Oct 1, 2009
    #4
    necro thread, but thought I might as well post what the problem was for the archives. Hard drive was overheating and shutting itself down for thermal protection. Whether there was some other problem I don't know - I rotated it into a extra drive slot where it was very infrequently used, and had no more problems with it.

    Maybe drives that run extra hot for whatever reason are a poor choice to run in uncooled bare docks like these.
     
  5. rtrt, Dec 3, 2010
    Last edited: Aug 13, 2011
  6. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #6
    Quite possible.

    In this case, it's actually attached to the internal SATA ports, which has a max cable length of 1.0 meters (passive connection). Worst yet, the adapter used tends to add contact resistance to the mix, which lowers the signal voltage further. Thus shortening the overall length the signal will remain stable.

    So an eSATA card may be needed (runs at a slightly higher voltage than internal ports; spec states 2.0 meters is the max cable length for eSATA).
     
  7. rtrt, Dec 4, 2010
    Last edited: Aug 13, 2011

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