Is OSX killing your harddisk?

Discussion in 'MacBook Pro' started by hzxu, Sep 28, 2009.

  1. hzxu macrumors regular

    Dec 17, 2008
    When I was using Ubuntu, there was a problem which causes Load_Cycle_Count increasing too fast, here's some background from ubuntudemon's blog:

    I downloaded and installed MacPorts, then use "sudo port install smartmontools" to install smartmontools, then check LCC by "sudo smartctl -a /dev/disk0" for first harddisk, if you have several harddisks, change '0' at the end to 1, 2, ...

    Then you should see lots of output message, among which, there is a Load_Cycle_Count, and Power_On_Hours, here are mine:

    9 Power_On_Hours 0x0012 100 100 000 Old_age Always - 326
    193 Load_Cycle_Count 0x0012 098 098 000 Old_age Always - 27691

    I've been using my Macbook Pro 13" for nearly a month, I think LCC is some value above 0 when I bought it, but don't know how much, I calculated 27691/326 and get 84 something, then use 600000/84=7142.85, the total amount of hour before LCC reaches 600000, subtract 326: 7142-326=6816, 6816/24=284(days)

    I am scared, I searched and found other people having the same problem:

    His case is better than mine:
    Power_On_Hours 0x0032 100 100 000 Old_age Always -109
    Load_Cycle_Count 0x0032 100 100 000 Old_age Always -2205

    In Ubuntu I can use hdparm -B 254 /dev/sda to solve the problem, in OSX there is a tool called hdapm, download its dmg file, copy the program to /usr/local/bin and optionally if you want to launch it every time you machine starts, copy the plist attribute file to /Library/LaunchDaemons, you may also change its programarguments's item2 from max to value between 0-255( max is 255). Usually I use 255 when the machine is on AC, 192 when on battery, manually in Terminal:
    for AC:
    hdapm disk0 max
    for Battery:
    hdapm disk0 192

    However, it seems the problem persists, LCC is still increasing(but not that fast), I guess it is the Sudden Motion Sensor ignores hdapm's setting and keep parking the head to protect harddisk. I'll investigate more about this.

    I want to hear you macbook users, do your machines have the problem?
  2. J the Ninja macrumors 68000

    Jul 14, 2008
    sudo pmset -a disksleep 0 sms 0

    ^OS X will NEVER put your drive to sleep except for a full system sleep. I suggest you read the pmset man page, you are REALLY overthinking what it takes to solve this.

    Also, I might be wrong on this, but I thought the load cycle count went up whenever the drive spun up for any reason, including just booting up the machine, much less resuming from sleep.
  3. zbasarab macrumors member

    May 29, 2009
    i have aboslutely no clue what you are talking about.

    this is why i dont use GNU/Linux
  4. J the Ninja macrumors 68000

    Jul 14, 2008
    You aren't helping.
  5. maflynn Moderator


    Staff Member

    May 3, 2009
    I use Ubuntu, and I've never heard of this or even cared about it.

    I'm content with how OSX [and Ubuntu] handles disk i/o and the hard drive. I agree with the other poster. I think the OP is over thinking about this and it isn't really a problem.
  6. pprior macrumors 65816

    Aug 1, 2007
    the questions begs another: do we see abnormally high disk failure rates in mac computers?

    the answer is no.

    Therefore the original question is irrelevent, despite its academic interest to those that enjoy mucking around in obscure terminal commands.

    Me, I just pay, plug it in, and use it.
  7. mac2x macrumors 65816

    Sep 19, 2009
    The energy saver pref. pane has an option to put all hard disks to sleep whenever possible. I select that only for when running on battery power on my machine. Don't think there's any need to worry about load cycles. HDD's were meant to be used, and modern ones are better than ever. I'd worry more if it was an old HDD. And of course, back up your important data!
  8. m0no macrumors regular

    Jan 8, 2009
    I guess if you're worried you could just get a SSD, no? :)

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