Secure empty trash or Not

Discussion in 'macOS' started by Heavybarrel, Sep 18, 2014.

  1. Heavybarrel macrumors newbie

    Heavybarrel

    Joined:
    Sep 13, 2014
    #1
    Hi,

    I'm wondering if I should always securely empty the trash bin, or just default empty trash. Emptying the trash securely always seems to take a lot longer than normal. I know that when empty the trash securely, the compressed space is overwritten immediately, but does that even matter?

    Also, why do Mac's take so long to empty the trash, regardless if your emptying it securely or not.
     
  2. Mr. Retrofire macrumors 601

    Mr. Retrofire

    Joined:
    Mar 2, 2010
    Location:
    www.emiliana.cl/en
    #2
    Compressed space?
     
  3. Heavybarrel thread starter macrumors newbie

    Heavybarrel

    Joined:
    Sep 13, 2014
    #3
    In my understanding, when you delete files, they don't just vanish. The mac just compress the files/data, and new data can be written on top of it. Isn't that how it works?
     
  4. Fishrrman macrumors G4

    Joined:
    Feb 20, 2009
    #4
    Whether you need to use the "secure" empty trash or not,
    Depends upon WHAT you're trashing...

    That's about it...
     
  5. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #5
    No, nothing is compressed. The OS just overwrites the space that was used by those files so they cannot be recovered. If you are not particularly concerned about somebody recovering these files, there is no need to do secure empty trash.
     
  6. Heavybarrel thread starter macrumors newbie

    Heavybarrel

    Joined:
    Sep 13, 2014
    #6
    Secure empty trash doesn't give me extra space does it? I mean I will recover the same amount of disk space regardless if i secure empty trash or not, right?
     
  7. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #7
    Yep... same.
     
  8. 556fmjoe macrumors 65816

    556fmjoe

    Joined:
    Apr 19, 2014
    #8
    Regular deletion of files only removes the path to the data. Overwriting the data actually removes it. This what the secure option does. Underneath, it runs the srm tool, though it is a modified version for HFS+ that overwrites both the data fork and the metadata fork.

    If you have a traditional magnetic HDD, overwriting is important for security because it makes recovery of that data nearly impossible by obscuring the patterns written on the platters with random data. Even a single overwrite would take extremely specialized equipment to recover from, if it could be done at all.

    On an SSD, overwriting does little to nothing to improve security if you have TRIM enabled. In that case, a regular delete is very effective. It still isn't enough to ensure total erasure though. Securely erasing data from SSDs is very difficult, maybe even impossible due to wear leveling, garbage collection, and the fact that you cannot access the raw cells directly; you must go through the drive controller first.
     

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