How to sleep a MP with Raid card?

Discussion in 'Mac Pro' started by gugucom, Oct 9, 2010.

  1. gugucom macrumors 68020

    gugucom

    Joined:
    May 21, 2009
    Location:
    Munich, Germany
    #1
    I'm running my MP all the time because the Areca Raid card will not allow me to sleep it. It is actually a bit annoying because I sometimes sleep in the room and the MP 4.1 has relatively loud CPU heat sink fans.

    Has anybody figured a way to make the Areca cards sleep?
     
  2. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #2
    Unfortunately, it's not possible. As a general rule, RAID cards and sleep don't work together properly.

    What usually happens is if the system attempts to sleep, you end up losing the RAID card's initialization (power gets cut, and the firmware is no longer loaded). So you have to reboot the system in order to re-initialize the card. Sucks, but it's a fact that has to be dealt with.

    That leaves two options:
    Shut Down
    Leave it On​

    :(
     
  3. gugucom thread starter macrumors 68020

    gugucom

    Joined:
    May 21, 2009
    Location:
    Munich, Germany
    #3
    I think this is actually a very dumb design. Why don't they have a buffer battery to keep the Bios or EFI alife? That is only two dollars and you do not have the problem.
     
  4. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #4
    They're built primarily for servers, and aren't expected to be used with sleep (workstations for that matter, as they likely expect nightly operations to be running when the user has left the office for the night).

    I have had it work with sleep intermittently however under Windows (Win 7 being the most consistent). So you don't actually need a battery (seems OS X's sleep function needs work to make it work properly).
     
  5. dholaday macrumors member

    Joined:
    Mar 27, 2009
    #5
    Will using a battery back-up module with the Areca 1880ix allow the system to sleep without losing initialization of the RAID card?

    Does it make a difference if I use write-thru or write-back cache?

    Thanks
     
  6. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #6
    It won't help you in terms of sleep. The BBU is only there to retain the data stored in the cache.

    It has no affect on sleep, but performance wise, write-back is faster (writes aren't done every time <aka lazy write>, but in the event of a miss-read, the performance is half that of write-through).
     
  7. dholaday macrumors member

    Joined:
    Mar 27, 2009
    #7
    nanofrog. Thanks. I don't like the answer :eek: but now I know what is going on.
     

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