An open community 
of Macintosh users,
for Macintosh users.

FineTunedMac Dashboard widget now available! Download Here

Page 1 of 2 1 2 >
Topic Options
#36415 - 10/12/15 12:10 PM OnyX Secure Erase Warning for SSDs
MG2009 Online


Registered: 08/05/09
" . . . Regardless, once the file was in the trash and I clicked on Permanent Eraser, it always got deleted. Perhaps there is an exception somewhere, but I have yet to experience that."

I think that may be the case. I have had files that I wanted to securely erase and PE has refused to do so. Further, even with admin privileges, I was unable to unlock and alter the permissions in case those were preventing the action I wanted.

I do not wish to simply delete the file by emptying the trash - I want to securely delete. Meanwhile, the file just stubbornly sits there in the trash can . . . waiting for the date that never shows up!

P.S. The files in question are related to the SIZEWELL application which no longer is supported with Apple apps after 10.10 (Yosemite). I am not particularly interested in buying another app that can do this one job. Just wish PE could do it, though.

UPDATE: Thanks, Jon. I just downloaded and installed ONYX for El Cap. The files in my Trash not only deleted, but SECURELY deleted. The process was not "instant" as with simply deleting, but took about 15 seconds to run its course. (The Onyx log shows that said files were securely deleted, not just tossed from the trash.)

WARNING: Onyx states that their SECURE DELETE is "not recommended" for SSD and Fusion Drives.


Edited by joemikeb (10/14/15 06:46 AM)

Top
#36417 - 10/12/15 02:04 PM Re: OnyX Secure Erase Warning for SSDs [Re: MG2009]
jchuzi Online


Registered: 08/04/09
Loc: New York State
Thanks for the info about OnyX and the warning.


Edited by joemikeb (10/14/15 06:46 AM)
_________________________
Jon

OS 10.14.5, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365

Top
#36419 - 10/12/15 03:41 PM Re: OnyX Secure Erase Warning for SSDs [Re: jchuzi]
macnerd10 Offline


Registered: 08/04/09
Loc: Los Angeles, CA
In those instances (file in use), I click on “empty trash” with Option key pressed. It works.


Edited by joemikeb (10/14/15 06:47 AM)
_________________________
Alex
3.1 GHz 13" MacBook Pro 2015, 8 GB RAM, OS 10.11.2, Office 2011, TimeWarner Cable
2.8 GHz Xeon Mac Pro 2010, 16 GB RAM, OS 10.11.2, Office 2011, LAN

Top
#36420 - 10/12/15 05:04 PM Re: OnyX Secure Erase Warning for SSDs [Re: jchuzi]
artie505 Online


Registered: 08/04/09
I wonder if that OnyX warning should be extrapolated to Disk Utility's "Erase" functionality?

Edit: The "Secure Delete" issue is addressed here under "Finder", but I can't find any reference to "Secure Delete" & Disk Utility anywhere, so I guess there's no issue.


Edited by joemikeb (10/14/15 06:48 AM)
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36421 - 10/12/15 07:46 PM Re: OnyX Secure Erase Warning for SSDs [Re: artie505]
MG2009 Online


Registered: 08/05/09
. . . something about babies and bathwater . . . (hehehe)


Edited by joemikeb (10/14/15 06:47 AM)

Top
#36423 - 10/13/15 10:29 AM Re: OnyX Secure Erase Warning for SSDs [Re: artie505]
joemikeb Online

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
Originally Posted By: artie505
I wonder if that OnyX warning should be extrapolated to Disk Utility's "Erase" functionality?

As long as you have an SSD or Fusion Drive the answer is YES. That not only applies securely erasing a volume, it also applies to secure file deletion, file/volume defragmenting, or any other operation that repetitively writes to an SSD or PCle-based Flash Storage.


Edited by joemikeb (10/14/15 06:48 AM)
_________________________
joemikeb • moderator

Top
#36427 - 10/13/15 10:38 PM Re: OnyX Secure Erase Warning for SSDs [Re: joemikeb]
artie505 Online


Registered: 08/04/09
Originally Posted By: joemikeb
As long as you have an SSD or Fusion Drive the answer is YES. That not only applies securely erasing a volume, it also applies to secure file deletion, file/volume defragmenting, or any other operation that repetitively writes to an SSD or PCle-based Flash Storage.

Thanks.

So, the caveat is not El Cap specific and applies equally to my Snowy installation and to all versions of OS X, prior and in between.

Not to be facetious, but is a 1-pass zero all data that wouldn't write "repetitively" to my SSD permissible, or am I misunderstanding "repetitively"? (*)

And finally, how are we supposed to secure SSDs/computers with them for resale or other disposition without the secure erase feature?

(*) HUH? I just noticed that a 1-pass zero all data is no longer an option on my installation.

As per this screenshot, my 1, 7, and 35 pass erase/zero out options are now limited to deleted files, and only on a volume by volume, not a full disk (although it can't be seen in my screenshot), basis.

Is this something new that came about when I installed my SSD?

If so, why is it safer than zeroing all data?

Does Disk Utility change its options depending on whether it's looking at an SSD or HDD?

And, groan, do I have to unpack the HDD I've got packaged for mailing and see what I actually did when I [thought I had] zeroed all data?

Edit: What I'm seeing is not reflected in Disk Utility Help.

Edit 2: Brainstorm! I fired up my external HDD and found that Disk Utility sees it differently than it sees my SSD and continues to offer the secure erase options we've grown used to. (So, I did, in fact, do what I thought I had done to my up-for-sale HDD... Whew!)

I'll guess that this bi-polar behavior originated with OS X 10.6.8's recognition of SSDs, but I'll point out that it may only be as respects Apple branded drives, same as TRIM is only enabled on Apple branded drives. (SSD users running 10.6.8 can install Trim Enabler 2.2 for OS X 10.6.8 (small print beneath Download/Buy Now.)

TRIM has now been enabled on most, if not all, SSDs, but I'm not sure which version of OS X turned the trick.

(Mods: Should this be a new thread?)


Edited by joemikeb (10/14/15 06:48 AM)
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36433 - 10/14/15 07:42 AM Re: OnyX Secure Erase Warning for SSDs [Re: artie505]
joemikeb Online

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
Originally Posted By: artie505
So, the caveat is not El Cap specific and applies equally to my Snowy installation and to all versions of OS X, prior and in between.

As long as it is an SSD or PCie-based Flash Drive (same difference, just different bus connection)
Originally Posted By: artie505
Not to be facetious, but is a 1-pass zero all data that wouldn't write "repetitively" to my SSD permissible, or am I misunderstanding "repetitively"? (*)

"Repetitively" may not have been the best choice of words but in general that counts too.
Originally Posted By: artie505
And finally, how are we supposed to secure SSDs/computers with them for resale or other disposition without the secure erase feature?

The reason for a secure erase has always been residual magnetic impressions on the disk media that could, with enough time and money, be recovered. Sometimes up to three levels deep. With solid state media there is no residual magnetic or other impression that can be recovered which would seem to make multi-pass erasures unnecessary. There still remains the issue that a normal drive erase simply resets the volume directory to zero and does not do anything to the actual files themselves. As I understand it files on an SSD usually wind up scattered all over the drive and are therefore extremely difficult to piece together. While not perfect it would render recovery so difficult (ie. expensive) that it is unlikely unless the disk is known to contain access to LOTS of money or information that could be converted to money.

If that is not enough remove the SSD and replace it with a new blank device[/quote]
Disk drives and SSDs are both subject to forgetting the stored data and to wear which eventually makes the device unwritable and unreadable. Modern magnetic media (hard drives) can retain their data and remain readable and writeable so long that the drive mechanics will generally fail before that happens. But as has been noted elsewhere there aint no free lunch. In exchange for the dazzling speed of SSDs/PCie-based Flash Drives their data retention is MUCH shorter and they wear out a LOT faster. The better SSDs today have internal electronics that over time refresh the data so unless the drive goes for long periods of time without power the data is not lost.

Both SSDs and Hard Drives compensate for wear by providing spare data sectors that can be mapped in to replace sectors that for whatever reason can no longer be reliably written to or read. SSDs with 7 to 10% spare sectors are not uncommon. But once again SSDs wear a LOT faster than hard drives. Secure erasure as used on hard disks is therefore not advised because of the unnecessary contribution to wear.

Since you brought up TRIM, newer model SSDs often have the TRIM function in firmware and like the automatic internal "refresh" it is done transparently and does not rely on the OS or utilities to be performed.
Originally Posted By: artie505
Mods: Should this be a new thread?

Consider it done.


Edited by joemikeb (10/14/15 07:44 AM)
_________________________
joemikeb • moderator

Top
#36435 - 10/14/15 10:05 AM Re: OnyX Secure Erase Warning for SSDs [Re: joemikeb]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
Originally Posted By: joemikeb
"Repetitively" may not have been the best choice of words but in general that counts too.
Originally Posted By: artie505
And finally, how are we supposed to secure SSDs/computers with them for resale or other disposition without the secure erase feature?

The reason for a secure erase has always been residual magnetic impressions on the disk media that could, with enough time and money, be recovered. Sometimes up to three levels deep. With solid state media there is no residual magnetic or other impression that can be recovered which would seem to make multi-pass erasures unnecessary. There still remains the issue that a normal drive erase simply resets the volume directory to zero and does not do anything to the actual files themselves. As I understand it files on an SSD usually wind up scattered all over the drive and are therefore extremely difficult to piece together. While not perfect it would render recovery so difficult (ie. expensive) that it is unlikely unless the disk is known to contain access to LOTS of money or information that could be converted to money.
...
Since you brought up TRIM, newer model SSDs often have the TRIM function in firmware and like the automatic internal "refresh" it is done transparently and does not rely on the OS or utilities to be performed.
Originally Posted By: artie505
Mods: Should this be a new thread?

Consider it done.


TRIM is actually a game-changer in data recovery post-erase with SSDs. Recently I've been doing some research prior to developing some flash-based hardware libraries, with the design goal of being able to append log files over a long duration of time while reducing flash wear. Since traditional spinning media don't mind writing over the same data many times, very high use areas aren't at risk. While most people look at the (usually 32KB) blocks where files are frequently changed, that is only the third most written to area on the drive. The second is the directory, where files are added, removed, change size, or otherwise altered. (file "last access" dates are also changed, so even file read operations lead to a directory write) The biggest area of write activity is on the free-space-map, which changes continuously during most disk write activity.

Minor segway: This has led to me developing a three-tier approach to writes, because with flash memory you must "reset" an entire block if you want to change even a single byte in its area. It's these "resets" ("erases") that are limited in number before the block wears out and is unable to be successfully erased. This is necessary because while I can easily write a single byte to a log file almost continuously without erasing, I need to track file size and I can't be erasing an entire directory and free space map block every time I write a byte. I would very quickly destroy the block's ability to be erased.

TRIM serves a related function, due to the time it takes to erase a block. Wiping a flash drive would not only take around the same magnitude of time to erase as spinning media, but it would also use up a write on each block. TRIM tells the drive to "mark that block as all zeros" as though it had been erased. But it wasn't erased. The controller has its own block use map, separate from the file system's free space map, and any attempt to read any byte in a block marked trimmed will return a zero, regardless of what's actually there.

So wiping a hard drive via trims is almost instant, and any attempt to read any byte on the drive after that point will return a zero, leading you to believe that the data has been instantly zapped. But that's far from the truth. The controller is lying to you. Your data is all still present on the drive, you just can't access it. But all you need is the proper disk drivers on the computer to access other commands on the drive, to retrieve the actual data from any sector on the drive. This includes sectors marked as trimmed, AND sectors that have been "worn out" to the point where the drive has decommissioned them and is using another block (a "spare") in its place. This sparing process happens throughout the life of a SSD or spinning drive, and you (the user) permanently lose access to that block, and it probably did not get erased before being decommissioned. Spared blocks will be scattered all over your drive throughout its life, and may contain data you saved. (and since deleted, and even wiped, possibly years ago)

SSDs are worse for that, because (A) they spare a LOT more blocks over their lifespan than a spinning disk, and (B) TRIM is lying to you. It's also possible that some intelligent drive controllers may detect a secure wipe and translate it to an "implied trim". When disk utility tried to write zeros over the first 32kb of blocks on the drive, the drive may say "hey, that's basically a TRIM, we'll just TRIM it instead, and speed up the write process, and save a write cycle while we're at it". Good for them, bad for you. I don't know how many drives are out there that do that, but it's certainly higher than zero. OS X's disk utility recognizes drives supporting TRIM, and so when you "format" a drive, it simply calls TRIM(start to finish) and the drive instantly considers the entire drive all zeros. A secure erase won't do that, but there's no guarantee the drive won't imply a trim from a stream of zeros from disk utility.

SUMMARY: SSDs are harder to securely wipe than you think they are. Just because it looks empty doesn't guarantee it's five minutes away from a full data recovery by someone with the right tools. (and I happen to know someone here locally that has said tools... it's not theory, it's reality and I've seen it happen) Even if you succeed in writing zeros to the full range of accessible blocks, you're virtually guaranteed to still have data in the spared blocks that are out of your reach, again available for recovery by someone with the right software or hardware. There's simply no way for you to know what's on those blocks or to wipe them. They might be a few web pages from safari's cache, or they might be your tax returns from 2006. Physical destruction is the only way to be reasonably certain the data is inaccessible.
_________________________
I work for the Department of Redundancy Department

Top
#36436 - 10/14/15 12:58 PM Re: OnyX Secure Erase Warning for SSDs [Re: Virtual1]
joemikeb Online

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
Many thanks V1 for the relatively succinct and very clear explanation. Obviously my understanding of TRIM was woefully inadequate. After reading it I decide to see what DoD and others recommend. Google revealed a large number of articles and white papers on securely erasing Solid State Media and not surprisingly no small number of contradictions. I will leave it to your curiosity to dig all those out, but the consensus seems to be…
  1. Traditional methods used to erase data on hard disks are not particularly effective and in fact some are totally ineffective on SSDs and that ignores the damage that may result from wearing out data blocks on the drive.
  2. The optimum solution would appear to be data encryption, ideally performed by the drive's firmware and not in software on the host. (Hardware encryption is a lot faster).
Item 2, that would imply the SSD should be encrypted from the get go if you intended to leave the drive in the computer when you pass it along. In other words security requires forethought and should never be an afterthought, but that is not a new concept — at least it shouldn't be.
_________________________
joemikeb • moderator

Top
#36437 - 10/14/15 01:32 PM Re: OnyX Secure Erase Warning for SSDs [Re: Virtual1]
grelber Offline


Registered: 08/05/09
Loc: North of 49th ||
Usage note re
Originally Posted By: Virtual1
Minor segway

The proper word is segue, meaning 'an uninterrupted transition from one piece of music or film scene to another.'
ORIGIN: Italian, literally 'follows'.

Segway is a trademark for a two-wheeled motorized personal vehicle consisting of a platform for the feet mounted above an axle and an upright post surmounted by handles.
ORIGIN: an invented word based on segue.

Top
#36448 - 10/15/15 04:49 AM Re: OnyX Secure Erase Warning for SSDs [Re: grelber]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
Originally Posted By: grelber
Usage note re
Originally Posted By: Virtual1
Minor segway

The proper word is segue, meaning 'an uninterrupted transition from one piece of music or film scene to another.'
ORIGIN: Italian, literally 'follows'.

Segway is a trademark for a two-wheeled motorized personal vehicle consisting of a platform for the feet mounted above an axle and an upright post surmounted by handles.
ORIGIN: an invented word based on segue.

ah yes I forgot. Segue is for going off a tangent. Segway is for going off a cliff.

and to address above, I recently posted on doing military grade wipes. Summary: NSA always insists on physical destruction (shredder, even for HDDs), everyone else (Military/DoD/etc) want it degaussed or incinerated.
_________________________
I work for the Department of Redundancy Department

Top
#36456 - 10/15/15 05:24 PM Re: OnyX Secure Erase Warning for SSDs [Re: Virtual1]
joemikeb Online

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
Originally Posted By: Virtual1
, I recently posted on doing military grade wipes. Summary: NSA always insists on physical destruction (shredder, even for HDDs), everyone else (Military/DoD/etc) want it degaussed or incinerated.

Since degaussing has no effect on SSDs I suppose that leaves incineration as the only option.
_________________________
joemikeb • moderator

Top
#36458 - 10/16/15 05:16 AM Re: OnyX Secure Erase Warning for SSDs [Re: joemikeb]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
Originally Posted By: joemikeb
Originally Posted By: Virtual1
, I recently posted on doing military grade wipes. Summary: NSA always insists on physical destruction (shredder, even for HDDs), everyone else (Military/DoD/etc) want it degaussed or incinerated.

Since degaussing has no effect on SSDs I suppose that leaves incineration as the only option.

I would beg to differ. Our "data destroyer" box has a chute. You place the hard drive(s) in the chute, and the machine feeds them in one at a time. A low hum is heard for the next ~20 seconds, after which point the drive drops out a lower chute on the other end, and the next drive is loaded in for its turn.

Drives that drop into the box are warm to the touch all over (the aluminum shell is warm) and the circuit board is also warm to the touch. IC chips are specifically warmer than the board, and often they are still crackling, popping, and hissing. Given that degaussing should not be able to directly heat aluminum, I have to assume the platters have gotten QUITE warm.

The manufacturer claims the degaussing process (1) degausses (erases) the platters, (2) destroys the read/write heads, and (3) destroys the ICs on the controller card. That ought to toast any SSD.

(after that process, no IDE/SATA interface will detect the controller card on the drive)
_________________________
I work for the Department of Redundancy Department

Top
#36459 - 10/16/15 07:10 AM Re: OnyX Secure Erase Warning for SSDs [Re: Virtual1]
artie505 Online


Registered: 08/04/09
Originally Posted By: Virtual1
You place the hard drive(s) in the chute....

The manufacturer claims the degaussing process (1) degausses (erases) the platters, (2) destroys the read/write heads, and (3) destroys the ICs on the controller card. That ought to toast any SSD. (Emphasis added)

Have you confused your terms? (SSDs with platters and read/write heads?)


Edited by artie505 (10/16/15 07:15 AM)
Edit Reason: More & less
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36462 - 10/16/15 09:54 AM Re: OnyX Secure Erase Warning for SSDs [Re: artie505]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
Originally Posted By: artie505
Originally Posted By: Virtual1
You place the hard drive(s) in the chute....

The manufacturer claims the degaussing process (1) degausses (erases) the platters, (2) destroys the read/write heads, and (3) destroys the ICs on the controller card. That ought to toast any SSD. (Emphasis added)

Have you confused your terms? (SSDs with platters and read/write heads?)

Nope! Solid State Drives do not survive degaussing machines. It turns the flash chips into crispy critters, same as it does with the head amp, controller, and stepper driver ICs on Spinning Disk Drives. But in that case, the chip damage is the most important result.
_________________________
I work for the Department of Redundancy Department

Top
#36469 - 10/16/15 04:40 PM Re: OnyX Secure Erase Warning for SSDs [Re: Virtual1]
artie505 Online


Registered: 08/04/09
Originally Posted By: Virtual1
Originally Posted By: artie505
Originally Posted By: Virtual1
You place the hard drive(s) in the chute....

The manufacturer claims the degaussing process (1) degausses (erases) the platters, (2) destroys the read/write heads, and (3) destroys the ICs on the controller card. That ought to toast any SSD. (Emphasis added)

Have you confused your terms? (SSDs with platters and read/write heads?)

Nope! Solid State Drives do not survive degaussing machines. It turns the flash chips into crispy critters, same as it does with the head amp, controller, and stepper driver ICs on Spinning Disk Drives. But in that case, the chip damage is the most important result.

I'll take you on your word that degaussing will "toast" an SSD, but if you reread your quote that I quoted you'll see that you described a process beginning with "place the hard drive(s) in the chute" and continuing on to "the degaussing process (1) degausses (erases) the platters, (2) destroys the read/write heads", and you then extrapolated what is clearly an HDD unfolding of events to SSDs.
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36471 - 10/17/15 02:23 AM Re: OnyX Secure Erase Warning for SSDs [Re: joemikeb]
artie505 Online


Registered: 08/04/09
Thanks to both you and V1 for your responses; encryption from the get-go having become an impossibility, they've induced me to back-burner my concerns until they change from "what ifs" to "what do I do nows".

I think, though, that the very important subject we've been discussing flies, by default, way too far under the radar and that people who need to know about it may not find out until too late, if ever.

Edit: I must have had my eyes crossed the other night, because I just took another look and found that Disk Utility offers me absolutely NO different erase options for my SSD than it does for my HDD.


Edited by artie505 (10/17/15 02:26 AM)
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36484 - 10/17/15 11:13 PM Re: OnyX Secure Erase Warning for SSDs [Re: joemikeb]
artie505 Online


Registered: 08/04/09
Originally Posted By: joemikeb
Originally Posted By: artie505
And finally, how are we supposed to secure SSDs/computers with them for resale or other disposition without the secure erase feature?

The reason for a secure erase has always been residual magnetic impressions on the disk media that could, with enough time and money, be recovered. Sometimes up to three levels deep. With solid state media there is no residual magnetic or other impression that can be recovered which would seem to make multi-pass erasures unnecessary. There still remains the issue that a normal drive erase simply resets the volume directory to zero and does not do anything to the actual files themselves. As I understand it files on an SSD usually wind up scattered all over the drive and are therefore extremely difficult to piece together. While not perfect it would render recovery so difficult (ie. expensive) that it is unlikely unless the disk is known to contain access to LOTS of money or information that could be converted to money.

That leaves the question hanging.

Regardless of the fact that files deleted from an SSD are apparently extremely difficult to recover, just passing one along without doing anything gives the next user a (possibly bootable) drive with whatever data hasn't suffered anticipatory deletion...perhaps even some that should have.

It seems to me that before an SSD is passed on it should at least be thrown into an enclosure and and have its entire contents command-deleted followed by emptying its trash. (Edit: Either that, or it should undergo a clean OS X installation.)


Edited by artie505 (10/18/15 03:11 AM)
Edit Reason: As per Harv
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36485 - 10/18/15 03:01 AM Re: OnyX Secure Erase Warning for SSDs [Re: artie505]
Pendragon Offline


Registered: 08/04/09
Loc: Georgetown, Texas, USA
Artie,

Perhaps it depends on the OS or app, but on my machine, Command+D is "Duplicate".

Regardless, your point is clear and I'm learning much from this thread. Thanks to all!
_________________________
Harv
27" i7 iMac (10.13.6), iPhone Xs Max (12.1)

Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36486 - 10/18/15 03:05 AM Re: OnyX Secure Erase Warning for SSDs [Re: Pendragon]
artie505 Online


Registered: 08/04/09
Oops! blush Should have said "have its entire contents command-deleted followed by emptying its trash".

Thanks for the heads-up, Harv.

Edit: By way of explanation, I've got "Move to trash" and "Empty trash" hot keyed to F-7 and F-6 and haven't used command-delete in more than 10 years...actually had to stop and think about the correct command. shocked


Edited by artie505 (10/18/15 03:18 AM)
Edit Reason: Finally got it right
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36645 - 10/24/15 02:24 PM Re: OnyX Secure Erase Warning for SSDs [Re: artie505]
slolerner Offline


Registered: 08/25/09
Loc: New York City
When I asked Apple how to wipe an SSD, they told me something like you write to 90% of the disk and then do it again and somehow it starts the 90% from the other end, like cutting a deck of cards or something. Dunno. Ever see how much info people can recover from an 'erased' phone? So things may be scattered, but why would, say, the pixels of a single photo not all be in the same place?

joemikeb: I remember they did tell me that the only thing that can be done is use encryption from the beginning.


Edited by slolerner (10/24/15 02:33 PM)
Edit Reason: more

Top
#36646 - 10/24/15 02:50 PM Re: OnyX Secure Erase Warning for SSDs [Re: slolerner]
artie505 Online


Registered: 08/04/09
I dunno about that...

According to OS X: About Disk Utility's erase free space feature

Quote:
Note: With an SSD drive, Secure Erase and Erasing Free Space are not available in Disk Utility. These options are not needed for an SSD drive because a standard erase makes it difficult to recover data from an SSD. For more security, consider turning on FileVault encryption when you start using your SSD drive.

In addition to apparently being contrary to what "Apple" told you, that echoes what's been said here about the difficulty of recovering info from an SSD, and the FileVault suggestion is right in line with joemike's post.

(Secure erase options for an SSD are still available in Snowy, possibly later versions of OS X; I'm not certain in which version they disappeared.)

The "inner workings" of SSDs...why data is scattered, among other things, is something I'll probably never (even try to) understand.
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
#36647 - 10/24/15 04:10 PM Re: OnyX Secure Erase Warning for SSDs [Re: artie505]
slolerner Offline


Registered: 08/25/09
Loc: New York City
I called "Apple" tech support and asked how to erase an SSD to resell a computer and that's what I was told. Maybe that's what THEY do when they refurbish.

Top
#36648 - 10/24/15 04:18 PM Re: OnyX Secure Erase Warning for SSDs [Re: slolerner]
artie505 Online


Registered: 08/04/09
Originally Posted By: slolerner
I called "Apple" tech support and asked how to erase an SSD to resell a computer and that's what I was told. Maybe that's what THEY do when they refurbish.

I'd call them back and direct them to my linked doc.

(I hope Apple doesn't do anything when they refurbish that they not only tell me to not do but take away my means to do it.)
_________________________
The new Great Equalizer is the SEND button.

In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

Top
Page 1 of 2 1 2 >

Moderator:  alternaut, dkmarsh, joemikeb