Forum Question: Empty Trash Less Memory

This question has been in my mind for some time. When you empty Trash,it says you can recover the data with software.When you secure empty trash it says,this is turned into meaningless data.
When you empty trash this must be kept on your hard drive,and this to me must must take up memory on your hard drive. The same has secure empty trash,this meaningless data must be on your hard drive,and this must take up memory has well. Over to you Gary.
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Mr Anthony Cotton

Comments: 12 Responses to “Empty Trash Less Memory”

    9/22/11 @ 12:00 pm

    First distinguish between memory and hard drive space. To very different things.
    Files do not use memory, they use hard drive space.
    When a file is deleted the reference to the file is deleted. It is like having a file cabinet where everything is perfectly organized. Then you grab a piece of paper from the file cabinet and put it in a trash can. No one can find the file in the file cabinet anymore. It isn’t there, but it is still in your office, just in a different place. If you were to count your papers in your file cabinet, you wouldn’t count the pieces of paper in the trash.
    When you empty the trash, it is like trash collection day. The truck takes your trash, with the paper, way. It is gone.
    When you secure empty the trash, it is like shredding. You destroy the paper.
    When you simply put something in the trash it is still on your hard drive. You can undo the move to the trash, or manually take it back out from the trash.
    When you empty the trash, the reference to the file is deleted at the space that the file took up is put back into the pool of free space on the drive. Any application or the system can overwrite that space now at any time. It is free space and there is nothing you need to do — it doesn’t “take up space” anymore. That space is the same as space on your hard drive that has never had anything in it.
    Now what happens when you use a data recovery tool is that this free space is examined and the recovery tool tries to find old files that haven’t been deleted yet. Kind of like going to the dump the day after your trash has been collected and seeing if some of it is still there. It may be, or it may not be. The more you use your Mac and the more you read and write files, the less likely the files can be recovered.
    And these sorts of tools are not necessary any more. Why? Because doing a backup with a tool like Time Machine is a much much better way to recover files.

    Michael
    9/22/11 @ 4:48 pm

    VERY well said! But in a nut-shell: Always Back Up:). Great explanation though.

    Michael
    9/22/11 @ 4:57 pm

    But Gary that also brings me to some thing I always notice using the Mac. First I always delete the trash regularly (I use Time Machine). However I noticed in the past and have not tried yet since updating to Lion, but let say I have some files I am transferring using a flash drive for example and I copy the files to the Mac. Once copied, I throw the files in the trash to copy more files from another computer. I had noticed in the past if I do not empty the trash can of the files I threw away from that flash drive, when I bring that flash drive to the another computer, it will show that “memory” used up. Again I have not tried this recently (I will though) but I noticed a few years back transferring music I had from a PC to a new Mac. I loaded the FD with music copied to the Mac, deleted the files but did not empty trash and when I got back to copying more data from PC it said drive was full. It was not till I mounted FD back to the Mac and “emptied” trash can. Is this still the case as far as you know?

      9/22/11 @ 5:07 pm

      Yes. You have to empty the trash with the flash drive connected to clear the space.

    Mr Anthony Cotton
    9/23/11 @ 11:18 am

    Thanks, I thought the way you explained it was the way i looked at it. About the the trash man coming once a week,but what i wanted to know was that naturally i thought it was one thing and that was the memory Example -10GB and when you have emptied a lot of trash i thought this reduced the 10GB. So what is the memory used for Gary (sorry for being ignorant) I back up my files onto an external hard drive.

    Mr Anthony Cotton
    9/23/11 @ 11:53 am

    Yes this is one misunderstood,and its very common to mix the two up. It could save you money. I have just Googled it, and needless to say,its a very big topic. I took a couple of screen shots that made it more clear to understand (with pictures)
    Now i understand what you mean, but you have gave me a much better understanding. Thanks Gary

    Mr Anthony Cotton
    9/23/11 @ 11:58 am

    I have just clicked on your link and thats one of the sites i had a look at.
    You have completely answered my question as far as i am concerned.
    Thanks Gary

    Mr Anthony Cotton
    9/23/11 @ 12:37 pm

    Just to confirm my iMac reads Capacity 1TB Medium Type Rotational, this is the Hard Drive. Gary

    Mr Anthony Cotton
    9/27/11 @ 11:44 am

    I just remembered that these Apple downloads for upgrading things ect…Does these take up memory Gary.

      9/27/11 @ 12:02 pm

      Updates use disk space, not memory. And once the update has been applied, then the update files are remove. So the short answer is no.

    Mr Anthony Cotton
    10/2/11 @ 10:28 am

    I just thought of that afterwards, the updates. I would say i am very much wiser now about this topic. Thanks to you Gary.

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