What happens to the Trash when emptied

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JAD2014 Author

Level 1

7 points

What happens to the Trash when emptied

Hi, this may seem like a basic question but...when I was using a PC, I understood that even when you deleted a document and then emptied the recycle "bin" the original file did not actually get deleted from the hard drive or other media, but simply that the OS was able to re-use that space as and when it needed to and in this case the original file may be eventually completely or partially overwritten. The outcome of this was that over a period of time you had to "defrag" your hard-drive as a basic housekeeping chore. Can anyone tell me whether the same basic storage process occurs with a MAC device? I would like to be sure that when I delete some files and empty the Trash can, they are truly unobtainable by any malware or other unauthorised access, also whether I need to from time to time defrag the MAC hard drive???

iMac (21.5-inch, Late 2013), OS X Yosemite (10.10)

Posted on Sep 16, 2015 8:26 AM

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Answer 1

VikingOSX

Level 10

122,988 points

Sep 16, 2015 8:43 AM in response to JAD2014

Yosemite Securely erasing your deleted files. You can also press the command key when you right-click to empty the Trash. It will change to Secure Empty Trash. This is a 1x overwrite of your trash items.

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Answer 2

JimmyCMPIT

Level 7

29,306 points

Sep 16, 2015 8:47 AM in response to JAD2014

After emptying the trash the file does exist in some form that can be rescued with various methods and to a varied degree of success but as time and disk usage go on the likelihood of that file no longer existing increases dramatically. The space occupied by that file is available to the user even if the file is still present it it's readily inaccessible but not entirely removed form.

When you secure empty trash the files are overwritten with data making them virtually useless if you do "rescue" them.

for more info on your defragmentation question see this link

How to safely defrag a Mac's hard drive

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Answer 3

JAD2014 Author

Level 1

7 points

Sep 16, 2015 8:57 AM in response to VikingOSX

Brilliant, thank you!

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Answer 4

JAD2014 Author

Level 1

7 points

Sep 16, 2015 9:02 AM in response to JimmyCMPIT

Very useful advice, thank you!

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Answer 5

rccharles

Level 6

13,027 points

Sep 16, 2015 10:56 AM in response to JAD2014

Mac OS X has a built in fragmentation in the file system software [ what a concept ]. In most instances it is enough. The average user is unlikely to need defragmentation. I haven't read about a general recommendations to defragment in these forms. Defragmenttation is a Windows worry.

Should you be doing excessive file creates & deletions, defragmentation may prove helpful. I would be more interested in following disk performance in a production system. I think when defrgmentation became a worry, I'd look into a ssd.

Robert

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