Forced Shutdown of rMBP - First Time in a Year!

Discussion in 'MacBook Pro' started by crellion, Oct 19, 2014.

  1. crellion macrumors regular

    Joined:
    Oct 22, 2009
    #1
    I must say I have been on a winning streak with my rMBP - never froze on me for an entire year since I got it!

    But looks like my luck ran out today when I was running my Splashtop Remote Desktop program and the system froze up. Not worked except the mouse. I tried Force Quit and everything - nothing happened.

    So I had to do my last resort - hold down the Power Button. Shutdown and back on.

    Back in the day - people used to worry these forced shutdowns messed up the HDD, but since all rMBP use SDD to begin with - should I be concerned of some hardware being damaged from this occurrence?
     
  2. 556fmjoe macrumors 65816

    556fmjoe

    Joined:
    Apr 19, 2014
    #2
    No hardware is damaged by forced shutdowns, but it is possible for some data loss or filesystem metadata inconsistency to occur. This is true regardless of whether it is a SSD or HDD.

    Computers don't write directly to the hard disk because that would be very slow. Instead, they write data to the drive's buffer cache, then write from that buffer to the actual storage media. When you shutdown normally, all the data currently sitting in the drive's buffer is written to the drive before the partitions are unmounted. A forced shutdown kills the power without writing that data to the disk, which causes it to be lost. This can be a problem if the metadata that tells your system where your files are (among other important things) is lost.

    There are ways for filesystems to mitigate this problem though. Journaling filesystems such as HFS+ write the changes they make to a journal, so if power is suddenly lost and you reboot, the filesystem can simply refer to that journal and carry out the operations again until the system is consistent. There still is a risk of data corruption, but it is lessened.

    This is over-simplified, but the main point is that hardware is generally not damaged by forced shutdowns.
     
  3. JPIndustrie macrumors 6502a

    JPIndustrie

    Joined:
    Mar 12, 2008
    Location:
    Queens, NY
    #3
    haha you're kidding right

    there are plenty times when I've had to hold down the power button to reboot on my '14 15" rMBP, no risk for issue especially with Apple's highly integrated logic board. How do you think Sleep would function without it? ;) :apple:
     
  4. crellion thread starter macrumors regular

    Joined:
    Oct 22, 2009
    #4
    lol - I know - I must say I am impressed with OS X - this thing is as solid as a rock!

    And yes - I do consider it legendary performance when I don't even get a single freeze on a computer for an entire year - it has been bliss!

    other than today's hiccup - I hope it stays that way!
     
  5. KUguardgrl13 macrumors 68020

    KUguardgrl13

    Joined:
    May 16, 2013
    Location:
    Kansas, USA
    #5
    Wow! I have a late-13 rMBP that suffered from "trackpadgate". The only way I knew how to fix it was to force shutdown. Luckily they fixed it eventually! Haven't had too many problems since other than a random sleep/wake issue or two recently.
     
  6. crellion thread starter macrumors regular

    Joined:
    Oct 22, 2009
    #6
    One thing I read (and this is more regarding a plugged in desktop) - is that doing a hard-shutdown via holding the Power Button is actually safer than simply unplugging the power to the computer.

    Because there is a difference between holding the Power Button (which is controlled by the motherboard) and directly unplugging it via the PSU.

    Apparently this can wear down the PSU faster by simply unplugging it versus having the motherboard initiate the command.

    I'm not sure if what I read has any weight to it, but other than "potential" software (not hardware) corruption (which the worst case is reinstalling everything) to the HDD, is there really no other "physical" damage to a computer from forced shutdowns?
     

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