Summary: Until OS X El Capitan, it was an easy task to secure empty trash by right-clicking on the trash and pressing Command key to make ‘Empty Trash’ switch to ‘Secure Empty Trash’. However, the fun of securely eliminating deleted files is missing in OS X El Capitan like the way it was. Why did Apple choose to remove it from this version of OS X? And why it existed on below versions of OS X until now?
Secure Empty Trash – A problem?
Quite frankly yes, secure empty trash has been a problem especially for Solid State Drives & fusion drives that are the integration of SSDs & hard drives. Secure empty trash caused unnecessary wear and tear on solid-state drives. Hence Apple chooses to remove it from OS X El Capitan.
How Apple filled the Gap?
How did Apple fill the void in place of ‘Secure Empty Trash’ option? The answer is ‘Delete Immediately’ option, which arises when you right-click a file in the trash. See below example:
Another very simple method of securely deleting file or group of files it to select the file(s) and press this key combination – CMD + OPTION + DELETE. This will give you below the message.
Be very sure to proceed with the DELETE button since the selected files will be wiped out from Mac hard drive. Hope you have installed a strict Mac hard drive backup utility to clone your Mac hard drives.
Why erase Mac files securely on OS X at first place?
Q) Why there exists a need for securely wiping files or securely erasing a hard drive on OS X Mac? Find below helpful answer.
A) Whenever the files are deleted (i.e. trash emptied), the OS X eliminates only the index entry of that file(s) and doesn’t remove them from the hard drive location. However, OS X does allow other files to overwrite the deleted files from its location. On running a data recovery application on Mac OS X El Capitan, the software scans the entire hard disk drive for deleted entries and recovers them upon locating them from their original drive addresses. Some users do not wish to get their files recovered after deletion, hence securely wiping Mac files and hard drives are recommended. Secure wiping Mac is the best practice before donating and selling Mac and/or its hard disk drive.
Secure erasure on OS X El Capitan
- Using third party Mac wiping tools
Mac hard drive wiping utilities are readily available for OS X El Capitan and below versions of OS X. These Mac wiping utilities are capable of securely wiping individual files, multiple files, folders, Internet and browsing activities, instant messaging, System traces and file history. Take a free tour of Stellar Mac Wipe utility to securely erase files and hard drives on El Capitan. This utility allows the creation of bootable DVD in order to secure wipe Macintosh HD (startup disk).
Whatsoever can’t be done with GUI on Mac, can be performed using Terminal.app since Terminal converts your command line inputs into output. Let’s understand those commands to secure erase files on OS X El Capitan:
rm – rP /path/to/file-or-folder
srm – rfv – s /path/to/file-or-folder
- rm – (file removal command, ‘r’ denotes recursive deletion)
- rP – (request for overwriting of the deleted file)
- srm – (request to secure removal of files)
- f – (force confirmation)
- v – (file information)
- Minus s – (single pass erase)
- if using Minus m – (seven pass erase)
- if using Minus z – (zeroes overwriting)
- Free space erase on Mac hard drive
Free space erasure option is removed from Mac’s Disk Utility but with the help of below command line, one can still perform free spaces erase on a given hard drive.
diskutil secureErase freespace LEVEL /Volumes/DRIVENAME
Replace LEVEL with (0 – 4), where 0 is a single pass of zeroes, 1 denotes single pass of random numbers, 2 denotes 7 passes, 3 denotes 35 passes and 4 indicates 3 passes erase. Please note that securely erasing free spaces is a time-consuming process.
Not everything is removed from OS X El Capitan
You can still securely wipe mounted hard disk drives and external hard drive with Disk Utility. Below is the process:
Step 1: Make sure the hard drive is mounted in Disk Utility. In case of external hard drive make sure it is connected & mounted. From Disk Utility, select the hard drive from the left-hand pane.
Step 2: Click ‘Erase’ and again click on Security Options.
Step 3: You have to choose between Fastest and Most Secure methods of securely wiping the Mac hard disk drive. Click OK << Erase to start the process.
You cannot select Apple startup disk (Macintosh HD) for erasure until unless you boot up the Mac from another media and erase the startup hard drive securely with the help of a 3rd party Mac wiping utility. Hope that Apple’s decision to remove the secure empty trash will not bother you much since there still exists various tricks to achieve secure wiping of files from Mac OS X.
Also read: How to recover permanently trashed files formats.