Error Reformatting HD: "Securely erasing data to prevent recovery failed"

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Level 1

4 points

Error Reformatting HD: "Securely erasing data to prevent recovery failed"

I have a 4 TB G-Tech external optical drive connected via Firewire 800 that I use for Time Machine. I began having issues with failed backups, and after investigating Pondini's Time Machine Tips I decided I needed to erase the drive and start from scratch.

Using Disk Utility I've tried twice to reformat using the "Zero Out Data" option, and both times it failed,displaying this error "Securely erasing data to prevent recovery failed.". The 1st time it failed after about 20 hours, the 2nd time after 12 hours. If I reformat without the "Zero Out Data" option, formatting appears to work, and running Disk Utility's Repair Disk function afterwards reports no problems.

Given the failed TM backups and then the reformatting errors, I'm concerned that there may be hardware issues with the drive and I would appreciate any input.

MacBook Pro, OS X Mavericks (10.9.2), MacBook Pro 9,1 2.6 GHz i7

Posted on Dec 6, 2014 3:56 PM

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Answer 1

Drew Reece

Level 6

10,684 points

Dec 6, 2014 4:25 PM in response to MacVal

It's possible the disk is unable to write in a reliable way, however it could also be your current OS or hardware. Does the Firewire connection seem OK generally? You may have log entries from the time of the failure, but it is hard to go back unless you know the times things stopped working. Logs are shown in /Applications/Utilities/Console, Disk Utility has it's own log file.

Disk Utility will give you a SMART status overview, but you may not be able to access that since SMART requires 'on board connections', you would need to take the disk out & install it into another Mac to see that.

SMART Reporter may get around this limitation…

http://www.corecode.at/smartreporter/ Interpreting SMART output can be a tough.

I think to test the disk correctly you would need to use an integrity checker, like Tech Tool Pro or Drive Genius.

There are other tools on free OS's like 'badblocks' on Linux that could help if you are able to download & create a bootable USB stick or CD/DVD.

http://manpages.ubuntu.com/manpages/intrepid/man8/badblocks.8.html

http://www.ultimatebootcd.com has many tools.

Some claim to have had badblocks working on OS X (part of the Linux ext2fs package), but I don't expect that is practical unless you are able to compile yourself, the info I saw is many years old.

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Answer 2

MacVal Author

Level 1

4 points

Dec 6, 2014 7:07 PM in response to Drew Reece

Thanks for the input.

- "Does the Firewire connection seem OK generally"

Yes, but just in case I used a different cable for the 2nd attempt, which also failed.

- "You may have log entries from the time of the failure"

I did grab the log just in case, although I'm not really up to speed on what it all means. Details below.

As seen in the log I also tried using the partition option to reformat, and that failed too, but just the once. I tried it a few more times and it worked fine.

So after one of the successful reformats, I dragged a bunch of files onto the drive and they seemed to copy over fine. Then out of curiosity I ran DiskWarrior, and it found no errors. I ran Disk Utility's First Aid again and it found nothing wrong either. I suppose I could try starting Time Machine again and keep a close eye on it over the next while.

2014-12-05 22:31:11 -0800: Disk Utility started.

2014-12-05 22:32:15 -0800: Preparing to erase : “Untitled”

2014-12-05 22:32:15 -0800: Partition Scheme: GUID Partition Table

2014-12-05 22:32:15 -0800: 1 volume will be created

2014-12-05 22:32:15 -0800: Name : “Untitled”

2014-12-05 22:32:15 -0800: Size : 4 TB

2014-12-05 22:32:15 -0800: File system : Mac OS Extended (Journaled)

2014-12-05 22:32:15 -0800: Unmounting disk

2014-12-05 22:32:15 -0800: Creating the partition map

2014-12-05 22:32:16 -0800: Waiting for the disks to reappear

2014-12-05 22:32:16 -0800: Formatting disk1s2 as Mac OS Extended (Journaled) with name Untitled

2014-12-05 22:32:31 -0800: Initialized /dev/rdisk1s2 as a 4 TB case-insensitive HFS Plus volume with a 311296k journal

2014-12-05 22:32:31 -0800: Mounting disk

2014-12-05 22:32:33 -0800: Erase complete.

2014-12-05 22:32:33 -0800:

2014-12-05 22:33:16 -0800: Preparing to zero disk : “Time Machine HD”

2014-12-05 22:33:16 -0800: 1 Pass Secure Erase

2014-12-06 14:56:27 -0800: Secure Disk Erase failed with the error:

Securely erasing data to prevent recovery failed.

2014-12-06 14:56:28 -0800: Preparing to erase : “Time Machine HD”

2014-12-06 14:56:28 -0800: Partition Scheme: GUID Partition Table

2014-12-06 14:56:28 -0800: 1 volume will be created

2014-12-06 14:56:28 -0800: Name : “Time Machine HD”

2014-12-06 14:56:28 -0800: Size : 4 TB

2014-12-06 14:56:28 -0800: File system : Mac OS Extended (Journaled)

2014-12-06 14:56:28 -0800: Error with partition Assert: internal error or unimplemented

2014-12-06 14:56:28 -0800: Erase complete.

2014-12-06 14:56:28 -0800:

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Answer 3

Drew Reece

Level 6

10,684 points

Dec 7, 2014 10:18 AM in response to MacVal

The log is not very helpful to me either - sorry.

The concern I have is that the zero option attempts to write to every available area of the disk. A normal 'format volume' doesn't do this, it just sets up a valid partition table & marks the space as available.

I'd be concerned that you may have a bad block (or multiple) on the disk somewhere. The disk controller (or the OS) should attempt to isolate these, which means something has gone wrong in this case.

The only way I could trust that disk would be to verify it with a tool that writes & then verifies the the data across the entire volume (or even better across the entire disk ignoring any volumes - erasing the data in the process).

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Answer 4

MacVal Author

Level 1

4 points

Dec 10, 2014 10:49 AM in response to Drew Reece

Thanks again for the input.

I realized I had one more option I could test. I have an old iMac, so I used it to try zeroing-out the HD. It took over a day but completed wit no errors, so I decided to try a Time Machine backup again (via firewire 800). I started backing up 1.5 TB last night, and after running overnight it has only completed 115 GB. At that rate it would take days to complete which can't be normal (?) even for a first-time backup. I cancelled the backup and ran DiskWarrior and Disk Utility again, and they still don't find any errors. But given all the odd behaviour I would think something must be wrong with this disk.

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Answer 5

Drew Reece

Level 6

10,684 points

Dec 10, 2014 12:43 PM in response to MacVal

This massive list of bit rates will give you an indication os the limitations of various protocols…

https://en.wikipedia.org/wiki/List_of_device_bit_rates

Firewire 800 shows around 98MB/s (MegaBytes per second) for the theoretical maximum. Real world is more like 40-60MB/s in my experience.

Wolfram is good at converting…

http://www.wolframalpha.com/input/?i=115GB+at+40MB%2Fs

It suggests about 50 minutes would be enough for the 115GB.

Activity Monitor will give you a rough figure for data read/ writes per second - it covers the entire OS so you can only use it as a guide, see what it maxes out at during a Time Machine backup to the disk in question. Remove any other connected Firewire devices - they shouldn't interfere but I have seen them effect other devices on occasion.

Another thing to bear in mind is that if you have a lot of tiny files they can take longer to write than one massive file.

The disk itself could also be fine - sometimes the controller is the issue. Placing it into another case would isolate that.

Blackmagic make a speed test tool, otherwise you will need to buy some more testing apps for OS X or use Linux distros to test the disk.

https://itunes.apple.com/us/app/blackmagic-disk-speed-test/id425264550?mt=12

Disk Warrior remaps disk catalogs, at least that is how I understand it work, meaning that damaged blocks may not be part of it's test suite. I think it scans for files & inserts them back into a working catalog, so that the filesystem is in good order.

To be honest this disk isn't inspiring confidence, I'd try to test on different hardware (ideally using a known good OS e.g. one with no third party apps installed).

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Answer 6

MacVal Author

Level 1

4 points

Dec 11, 2014 1:23 PM in response to Drew Reece

You're quite right, it does not inspire confidence.

But there is good news. The drive is about two and a half years old so warranty didn't even cross my mind at first. But just in case I thought I may as well check, and to my amazement the warranty is 3 years (it's a G-Technology "G-Drive"). I contacted their support department and the drive will indeed be replaced... a nice surprise.

I appreciate all the helpful suggestions and valuable links, some good resources there.

Many thanks.

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Answer 7

Drew Reece

Level 6

10,684 points

Dec 11, 2014 2:58 PM in response to MacVal

Hey, that's good news good luck with the new HD 🙂

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