Emptying trashcan with flash storage.

[esp.egelan]

Hello.
I just bought a new MacBook Pro with flash storage, I thought that with the flash storage files were actually deleted when you empty the trash can unlike with a regular HDD. But to my surprise you still have the option between simply emptying the trash can, or empty securely.

So can you still trace back old files that have been emptied? If not, whats the point of emptying securely?

Thanks!

 

[Jack426]

Hello.
I just bought a new MacBook Pro with flash storage, I thought that with the flash storage files were actually deleted when you empty the trash can unlike with a regular HDD. But to my surprise you still have the option between simply emptying the trash can, or empty securely.

So can you still trace back old files that have been emptied? If not, whats the point of emptying securely?

Thanks!

From what I understand, the method to recover data from SSDs is more complex (algorithm/software wise), but overall they act like regular HDDs, overwriting data only when space is needed. Emptying the trash tells the OS that the data is ready to be written over, but the data stays until it needs to be. Empty Securely, on the other hand, overwrites the "real" data with random data, until the random data needs to be re-written again, with "real" data.

If you think about it an SSD is basically a USB flash drive on steroids, and if you've ever accidentally deleted a file off your flash drive, you know it's quite easy for you to recover. All you need is a free recovery program, and a few minutes.

In short, if you really need to make sure the file is gone, empty securely. (Be prepared to wait quite a few minutes, depending on how much you have in your trash.) Otherwise, continue emptying the trash as normal.

 

[sarah362]

Hello.
I just bought a new MacBook Pro with flash storage, I thought that with the flash storage files were actually deleted when you empty the trash can unlike with a regular HDD. But to my surprise you still have the option between simply emptying the trash can, or empty securely.

So can you still trace back old files that have been emptied? If not, whats the point of emptying securely?

Thanks!

That's good isn't. Atleast user can give a thought before choosing b/w emptying and securely emptying the trash. The files deleted without any warning or message will surely shock users.

 

[esp.egelan]

From what I understand, the method to recover data from SSDs is more complex (algorithm/software wise), but overall they act like regular HDDs, overwriting data only when space is needed. Emptying the trash tells the OS that the data is ready to be written over, but the data stays until it needs to be. Empty Securely, on the other hand, overwrites the "real" data with random data, until the random data needs to be re-written again, with "real" data.

If you think about it an SSD is basically a USB flash drive on steroids, and if you've ever accidentally deleted a file off your flash drive, you know it's quite easy for you to recover. All you need is a free recovery program, and a few minutes.

In short, if you really need to make sure the file is gone, empty securely. (Be prepared to wait quite a few minutes, depending on how much you have in your trash.) Otherwise, continue emptying the trash as normal.

I thought an SSD needed to totally get rid of a file, so that it wouldn't fill up and damage the memory cells.

Thank you for the reply Jack

 

[Jack426]

I thought an SSD needed to totally get rid of a file, so that it wouldn't fill up and damage the memory cells.

Thank you for the reply Jack

No problem! (I've actually been learning more about SSD/HDD's myself.) As for what you said above, I've never heard of that before. I did however find a nice (long, but descriptive) article about SSD's. Now, this article is from '09, but I would think that it's still relevant in terms of how SSD's work. Below, is a small excerpt about the deletion process. Here is the articles link, if you're interested in reading. (I might finish the whole article myself, in my spare time.) http://www.anandtech.com/show/2738/7

When you delete a file in your OS, there is no reaction from either a hard drive or SSD. It isn’t until you overwrite the sector (on a hard drive) or page (on a SSD) that you actually lose the data. File recovery programs use this property to their advantage and that’s how they help you recover deleted files.

The key distinction between HDDs and SSDs however is what happens when you overwrite a file. While a HDD can simply write the new data to the same sector, a SSD will allocate a new (or previously used) page for the overwritten data. The page that contains the now invalid data will simply be marked as invalid and at some point it’ll get erased.

 

[esp.egelan]

No problem! (I've actually learning more about SSD/HDD's myself.) As for what you said above, I've never heard of that before. I did however find a nice (long, but descriptive) article about SSD's. Now, this article is from '09, but I would think that it's still relevant in terms of how SSD's work. Below, is a small excerpt about the deletion process. Here is the articles link, if you're interested in reading. (I might finish the whole article myself, in my spare time.) http://www.anandtech.com/show/2738/7

Cool, thanks man