What exactly does "Secure Empty Trash" do?

There's very little technical detail on the web about this. I'd like to understand exactly what secure empty trash does.
What method does it use to overwrite?
How does it deal with temp files?
Why does it take so long?
Why, when there's only one file in the trash, does it always claim it's erasing 9 files?
What other files is it erasing in addition to the visible trash contents?
Can it work across network connections and external drives?
Has the method changed in Leopard?
etc.. etc..
Feel free to get all technical, if you know the answers!
Thanks!

What method does it use to overwrite?
It writes over the files with 0's.
How does it deal with temp files?
Not sure what you mean. It treats any file in the trash the same. Could you elaborate?
Why does it take so long?
Because it has to first write over the item with 0's, then delete the item.
Why, when there's only one file in the trash, does it always claim it's erasing 9 files?
What other files is it erasing in addition to the visible trash contents?
It's a bug.
Can it work across network connections and external drives?
Yes.
Has the method changed in Leopard?
Not that I know of.

Similar Messages

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    Does using the secure empty trash option accomplish the same task as
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    The zero erase free space can be also be used to pre-eliminate potential unknown bad sectors on hard drives before wanted data is written to them, thus preventing future issues with data retention on hard drives.
    Disk Utility > Erase - (not moving the slider) will erase all data on the volume or partition selected, including wanted data. It just tells the file system the deleted data is ready for overwriting. Thus can be recovered using special software before it's overwritten on hard drives only.
    Disk Utility > Erase w/Security Option - (or moving the slider from the left) will secure erase all data on the volume or partition selected, including wanted data.
    It can vary on the operating system version used from zero pass, to 3x overwrite, to 7x overwrite to 35x overwrite (old version for days past of smaller drives, don't use on newer larger drives as it will take weeks to finish.)
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  • Does secure empty trash save disk space?

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    I am aware that everyone said that it doesn't save any disk space, because I read through the thread.
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  • Why does SECURE EMPTY TRASH take so long (several days)?

    I am using OS 10.3.9. I didn't empty the trash for quite a while, and several days ago clicked SECURE EMPTY TRASH. The emptying process began but has not finished even now! Does it take THAT much longer when one uses SECURE EMPTY TRASH? I see that the little message window for Trash says:
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    When you choose to Secure Empty Trash, the system
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    Mulder
    If my answer helped solve your problem, please
    consider awarding some points. Why
    Reward Points?
    OK, and thank you. You have answered my question; I now won't be worrying that something is awfy. The Secure Empty Trash is still emptying and it is down to about 77,000 items. I have clicked the YES, MY QUESTION HAS BEEN ANSWERED button and I appreciate your reassurance.
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  • I have 139 items in my Trash, When I click on secure empty trash to erase them it wants to erase 1309 items. Does anyone know what may be going on?

    I have 139 items in my Trash, When I click on secure empty trash to erase them it wants to erase 1309 items. Does anyone know what may be going on?

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  • Why does secure empty the trash take so long to perform?

    When I empty the 'secure trash' folder, it takes hours to perform what use to take seconds or minutes to do.

    Try deleting less at one time.
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    The only way to get rid of your data securely is to overwrite the entire disk several times with zeros (Disk Utility has a function for this, and it will take a long time.).
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  • Why Does Leopard Take an Eternity to Secure Empty Trash

    Hi Gang
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    After comparing the time it took 5 small files to empty in Leopard as compared to 1,500 Video Files in Tiger, it was astounding!
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    Thanx guys
    Whatever the reason, I've convinced, (at least in my particular case), there is a DEFINITE difference between my two systems. Secure Empty Trash in Leopard is problematic.
    Since I don't have anything important in this particular system, I'm willing to do a fresh install of Leopard. But as I said, there was already a fresh install performed in this 160 Gig 2004 system drive.
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  • Hi, Question about secure empty trash. I moved some Time Machine backup files to the trash from an external hard drive. Now I can't secure empty trash. It starts, finds 74,003 files, and does nothing. The external hard drive shows it's empty, but it isn't

    I moved some time machine backup files from an external USB hard drive to the trash. Tried secure empty trash. It counts 74,003 items, then just sits there. The external hard drive window shows it's empty, but the info pane says it only has 50G of memory left. I left the secure empty trash on over night. It did nothing. Ideas?
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    Relaunch the Finder, then from the Finder menu bar, select
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  • Secure Empty Trash & Trash Cache

    Am old Mac addict home user with Apple from day one but not a guru. Still have Apple IIE that runs like a clock. With 17 Macs in between, years ago when G3 would slow down, get sluggish and tired, I discovered that setting trash cache and deleting many thousands of cached files would invigorate the machine and restore it's original speed using Preferences in TechTool Pro V 3.
    Currently have TTP V4 in both G5 Pro Mac OS 10.5.6 and G5 Power Mac OS 10.4.11. Cleaning out old manuals got rid of TTP V2 and V3 manuals. Still have CDs but unfortunately no serial numbers. So, unable to open those programs. Micromat archives couldn't help. Also, unable to use TTP V4 preferences to set trash cache as there's no Preferences capability. Apparently it can be assumed there's no trash cache in current versions of TTP.
    Queried Micromat about trash cache who said to "Go into "System Preferences" --> "TechTool Protection". In the "Volume Usage" tab, you can set how many days you want TechTool Pro to save the "Trash History"." No joy as I couldn't figure out what that meant about "System Preferences" or how to do what they recommended.
    No problem as both G5s are operating fine. But, I'm curious.
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    Did you get a response to this? There is no solution listed, but it’s marked Solved.
    I think you are right that there is no longer a Trash Cache. I did a search and it came up with two files called Trash Cache, both were dated 2002, obviously many systems ago which probably came over with Migration Assistant from previous computers.
    The TechTool Protection is new with TTP 5. You won’t see it in System Preferences with TTP 4. That’s probably why you couldn’t figure out what they meant.
    Secure Empty Trash writes over those files which makes them nearly impossible to recover, so I don’t think you need to worry about them.

  • Secure Empty Trash reports wrong number of files

    Something that's been bugging me since even before OS 10.6: when I use Secure Empty Trash, the progress box always shows exactly 9 more files to be deleted than there are in the Trash (but counts down to 0 normally). Any idea what's up with that? All I can come up with is (a) it's intentional, and 9 fake files are created and then overwritten, as some sort of additional security (in which case, why 9?), or (b) there are 9 files in a .Trashes directory somewhere which cannot be deleted due to some extended attribute (in which case why no error message or notification?).
    Has anyone seen this? Ideas?

    In addition to your Home/Trash folder, there is a hidden .Trash folder at the top level of your hard drive, and also hidden .Trashes folders on each of your external drives, each containing a subfolder for every user account on your Mac. Even if they are all empty, the hidden folders themselves are all deleted when you Secure Empty, which accounts for the increased number of items that are being reported.

  • Secure emptying trash when getting privilges message

    Hi folks,
    Any help much appreciated.
    I decided the other day to use my Iomega Screenplay HD as a backup for my mac. Because it is NSCF (or whatever it is) I knew I'd have to re-format it in Fat32. I copied the contents of the HD to my Mac with the intention of writing it all back once the HD had been formatted.
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    I have lion and thought they would have fixed this.
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  • About Secure Empty Trash

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    Message was edited by: Tom Swift

    Thank you for the link to mireth.com. Within mireth I found this page which is exactly what I want to do and may do the trick:
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    ===============================================
    ++How to erase email instead of deleting email++
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    =============================================

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