Secure erase Samsung SSD

krishnaM

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Original poster
Sep 26, 2014
157
6
Hi guys,
I am trying to 'secure erase' and reinstall Mavericks on my Samsung SSD 850 PRO SSD. As that option is greyed out in disk utility for ssd, I tried to achieve that by enabling 'Filevault' first and then do a regular erase procedure. However for some reason I am not enable the Filevault in security option. Every time I tried to enable the Filevault and restart the mac, it freezes at startup screen and I not even able to sign in as the apple keyboard and mouse (both wired) are frozen. When I try to restart by pressing power button, it loads the mavericks but the with Filevault option disabled. I don't know what is that I am doing wrong. I'll appreciate any suggestions. Thanks

Krishna
 

Lucas Godfrey

macrumors 6502
Jul 12, 2010
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Somewhere between Here and There
Hi guys,
I am trying to 'secure erase' and reinstall Mavericks on my Samsung SSD 850 PRO SSD. As that option is greyed out in disk utility for ssd, I tried to achieve that by enabling 'Filevault' first and then do a regular erase procedure. However for some reason I am not enable the Filevault in security option. Every time I tried to enable the Filevault and restart the mac, it freezes at startup screen and I not even able to sign in as the apple keyboard and mouse (both wired) are frozen. When I try to restart by pressing power button, it loads the mavericks but the with Filevault option disabled. I don't know what is that I am doing wrong. I'll appreciate any suggestions. Thanks

Krishna
Secure erase is neither truly necessary on SSDs, nor really advised.
 
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krishnaM

macrumors regular
Original poster
Sep 26, 2014
157
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Thanks for the reply. But why should I not be able to enable filevault?
 

krishnaM

macrumors regular
Original poster
Sep 26, 2014
157
6
Upgrade to Yosemite or newer. Mavericks wasnt a very good OS.
I did as you advised. Downloaded El Capitan and tried to enable the file vault and now my macpro froze again at startup. I am not even able to choose boot drive holding the option button (to boot from my SuperDuper backup drive) at startup. PRAM reset didn't help either. I think the only option is to remove the drive and boot from SuperDuper drive and just do simple erase of SSD and forget about secure erasing. I am still confused why I am not able to enable file vault on the SSD.
 
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krishnaM

macrumors regular
Original poster
Sep 26, 2014
157
6
I did as you advised. Downloaded El Capitan and tried to enable the file vault and now my macpro froze again at startup. I am not able to choose boot drive holding the option button to boot from my SuperDuper backup drive at startup. PRAM reset didn't help either. I think the only option is to remove the drive and boot from SuperDuper drive and just do simple erase of SSD and forget about secure erasing. I am still confused why I am not able to enable file vault on the SSD.
I really wish if some one could explain why I am not able to enable file vault on my SSD. Is there some thing on this drive (viruso_O or a ghost:eek:) that is not letting the file vault turned on?

I hate to throw away the SSD due to superstitions:(.
 

xWhiplash

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Oct 21, 2009
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Whenever I reinstall my OS, I use my Parted Magic disc and perform an ATA Secure Erase on the SSD. This is NOT a DoD or a wipe secure erase. All this does is issue a voltage spike across the drive and marks all cells as writable. It only takes a few seconds to do. And the performance should be right back to when you first got it.
 

cruisin

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Apr 1, 2014
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Have you tried installing the OS and then enable filevault? The result will be the same.

Maybe the drive is incorrectly formatted. Did you delete all partitions then format? This should be the same as a new drive, so it should work.
Whenever I reinstall my OS, I use my Parted Magic disc and perform an ATA Secure Erase on the SSD. This is NOT a DoD or a wipe secure erase. All this does is issue a voltage spike across the drive and marks all cells as writable. It only takes a few seconds to do. And the performance should be right back to when you first got it.
Or you could just enable TRIM, which will do this every time for the empty blocks when the SSD is idle.
 

mbnt

macrumors member
Oct 22, 2003
37
16
NYC Metro Area
I really wish if some one could explain why I am not able to enable file vault on my SSD. Is there some thing on this drive (viruso_O or a ghost:eek:) that is not letting the file vault turned on?

I hate to throw away the SSD due to superstitions:(.
FileVault is awful. If you are that paranoid over someone looking or breaking into your computer, use VeraCrypt. FV is known to have oodles of problems.
 

xWhiplash

macrumors 68000
Oct 21, 2009
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Have you tried installing the OS and then enable filevault? The result will be the same.

Maybe the drive is incorrectly formatted. Did you delete all partitions then format? This should be the same as a new drive, so it should work.

Or you could just enable TRIM, which will do this every time for the empty blocks when the SSD is idle.
Or a simple 15 second operation will make it immediately fast. TRIM does not immediately remove your entire OS once you format the drive.
 

krishnaM

macrumors regular
Original poster
Sep 26, 2014
157
6
Have you tried installing the OS and then enable filevault? The result will be the same.

Maybe the drive is incorrectly formatted. Did you delete all partitions then format? This should be the same as a new drive, so it should work.

Or you could just enable TRIM, which will do this every time for the empty blocks when the SSD is idle.
I did format the drive with disk utility and there were no partitions.

I have a question regarding Trim enabling on Samsung SSD in El Capitan. Before this I had Mavericks and I used Cindori Trim Enabler for enabling trim. I read some where that the Trim function in El Capitan for third party drives has lot of bugs and Apple gives warning before enabling the trim. Is that true?
 

MrAverigeUser

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May 20, 2015
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I did format the drive with disk utility and there were no partitions.

I have a question regarding Trim enabling on Samsung SSD in El Capitan. Before this I had Mavericks and I used Cindori Trim Enabler for enabling trim. I read some where that the Trim function in El Capitan for third party drives has lot of bugs and Apple gives warning before enabling the trim. Is that true?
Yes, apple confessed massive issues even causing "data corruption".

If I were you, I ´d prefer Cindori´s "disk Sensei" It is a modified Trim Enabler (version 4.x) especially for the later OSX (after Mavericks)
The older "TrimEnabler" V. 3.x.x will not work.

https://www.cindori.org/trim-in-os-x-el-capitan/

https://www.cindori.org/safely-enable-trim-on-yosemite-and-el-capitan/

Read this for details:

https://www.cindori.org/trim-enabler-and-yosemite/
 
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cerberusss

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Aug 25, 2013
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I've filled an SSD with zeros in the past. Sure, the drive over-provisions so you can't clear all cells. But it seems good enough to me.

I just opened a terminal and gave the following command:
dd if=/dev/zero of=zero.bin bs=$((1024*1024*1024)) count=1

This creates a 1 gigabyte file. You can change the count parameter to create a 100 gig file or simply pass a large number so it completely fills your drive.
 

MrAverigeUser

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I've filled an SSD with zeros in the past. Sure, the drive over-provisions so you can't clear all cells. But it seems good enough to me.

I just opened a terminal and gave the following command:
dd if=/dev/zero of=zero.bin bs=$((1024*1024*1024)) count=1

This creates a 1 gigabyte file. You can change the count parameter to create a 100 gig file or simply pass a large number so it completely fills your drive.
Could you precise a bit more - so that people like me (not being familiar with terminal commands) could use this to erase "secure" SSDs? Let´s say, for a 1TB SSD….

Thanks.
 

cerberusss

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Could you precise a bit more - so that people like me (not being familiar with terminal commands) could use this to erase "secure" SSDs? Let´s say, for a 1TB SSD….

Thanks.
Open terminal and copy/paste the command, but change the last number from 1 to 1000. You'll get a 1000 gigabyte file which will fill your terabyte drive with zeros.
 
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AidenShaw

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I've filled an SSD with zeros in the past. Sure, the drive over-provisions so you can't clear all cells. But it seems good enough to me.
Oh my, oh my.

Doing that fills the drive to 100% of rated capacity, so that the garbage collection algorithms have to work their hardest just to keep some semblance of performance.

Filling it with zeroes is just about the worst thing that you can do to an SSD.
 

krishnaM

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Original poster
Sep 26, 2014
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Is that ATA secure erase procedure (mentioned above #7) using Parted Magic disc safe for SSD? It may cost $9 but I'll try that route if it doesn't have any deleterious effects on SSD.
 

bernuli

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Oct 10, 2011
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I had a similar issue with a Samsung drive and had to use Samsung's utility to reset the drive. The utility runs on Windows so I used BootCamp to run it. Once the drive was reset, it was smooth sailing.
 

flowrider

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Nov 23, 2012
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I read some where that the Trim function in El Capitan for third party drives has lot of bugs and Apple gives warning before enabling the trim. Is that true?
No, as was said above it's just a disclaimer

My Post from another thread:

I have 5 Samsung SSDs in my cMP. 1 SM951, 1 840 Pro, 2 840 EVOs and 1 original 840 series SSD. I have been using TRIM since the advent of TRIM Enabler, then with Disk Sensei and now with Apple's trimforce terminal command. All my SSDs are running just fine with TRIM enabled.
Yes, apple confessed massive issues even causing "data corruption".
That BS!

Lou
 

cerberusss

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Aug 25, 2013
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Oh my, oh my.
Filling it with zeroes is just about the worst thing that you can do to an SSD.
Sure, but we don't care about performance, right? When done, I simply remove those files and wait. The garbage collector or better yet, TRIM kicks in and I reboot and do a fresh reinstall (formatting the drive in the process).
[doublepost=1453796285][/doublepost]
Can I get a source on this claim? Or can mods just delete this for scaremongering?
Well, there's a whole list of devices that have bugs in this area, right?
https://github.com/torvalds/linux/blob/e64f638483a21105c7ce330d543fa1f1c35b5bc7/drivers/ata/libata-core.c#L4109-L4286
 

MrAverigeUser

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May 20, 2015
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Ok,
I have to correct a bit what I wrote above:

data corruption occurred, but (by now) seems "only" concerning MacBook pro 2015 with its own SSDs. Apple had to change their Firmware to fix the EXISTING data corruption problem with these machines .

http://appleinsider.com/articles/15/07/22/apple-fixes-2015-macbook-pro-flash-storage-issue-in-firmware-update

https://support.apple.com/kb/DL1830?locale=en_US

It seems , that at least at the moment this problem does not concern 3rd party SSDs in former machines nor is it known if this is concerning Trim function.

Sorry if I caused confusion.
 
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AidenShaw

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Feb 8, 2003
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Sure, but we don't care about performance, right? When done, I simply remove those files and wait. The garbage collector or better yet, TRIM kicks in and I reboot and do a fresh reinstall (formatting the drive in the process).
For your first point - by filling the drive 100%, you've crippled garbage collection. It can't clean up, because the drive is 100% full even after you've deleted the files. 100% full means that the garbage collector can only work with the hidden over-provisioned space.

Second, if you have TRIM you've wasted your time and needlessly added wear to the drive. With TRIM the blocks are reclaimed when the files are deleted - no need to create another file and delete it.

If you do want to make sure that free space is TRIM'd (perhaps because the SSD has been on a system without TRIM), find a utility that can instantly create huge files (that it, it creates huge files without writing into them), then delete the huge files. On Windows, creating a pagefile to fill the disk and removing it will accomplish this, and the SysInternals utility "contig" can create files of any length without filling them. (Note that such operations should require privilege, since the operation allows one to look at the contents of deleted files which used to be in that space.)

The "secure erase" command is by far the best way to go.

[The above refers to non-compressing SSDs like the Samsung that the OP has. If you have a SandForce SSD, writing zeroes would be an effective substitute for TRIM.]
 
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xWhiplash

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Oct 21, 2009
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TRIM is not necessary. I have had a SSD in my 2010 Mac Pro for over 3 years now with no performance issues.

It is not worth data corruption or causing your mac not to boot (in some cases when your OS updates and Trim Enabler causes it not to boot).
[doublepost=1453814798][/doublepost]
Is that ATA secure erase procedure (mentioned above #7) using Parted Magic disc safe for SSD? It may cost $9 but I'll try that route if it doesn't have any deleterious effects on SSD.
Yes. It issues an ATA Secure Erase command. Which nearly all SSDs treat as a voltage spike and mark all cells as read only. I use this even if I have had TRIM on the drive in the past.

Also, filling the drive with zeroes is impossible on most SSDs due to wear leveling. Unless they updated it?
 
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