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Many Mac users running a modern version of OS X El Capitan have noticed the Secure Erase Free Space feature has gone missing from Disk Utility. What the “Erase Free Space” feature did (and still does in prior versions of Mac OS X) was overwrite the free space on a drive to prevent file recovery, adding a layer of security and privacy to file removal, much in the way that Secure Empty Trash performed a similar function of overwriting data after removal.

For those wondering, these features were removed from the modern version of Disk Utility in Mac OS X because they do not work on SSD volumes, which are becoming more commonplace and nearly all Mac laptops ship with them by default now. But not everyone has an SSD drive, and thus some users may still wish to perform a secure erase of free space on their Mac hard disk. To achieve the same secure erase in modern versions of Mac OS X you’ll need to turn to the command line. And yes, this works to erase free space on older versions of Mac OS X too, but since they can do the same task with Disk Utility it’s perhaps a bit less relevant to the prior releases.

How to Secure Erase Free Space on Mac OS X El Capitan Drives via Command Line, Without Disk Utility

Back up your Mac before attempting to use these commands. The command line requires precise syntax and is unforgiving, improper commands could lead to the unintended removal of data you do not want to delete, permanently, as this is a secure erase function. You have been warned, so backup your Mac data first, then proceed at your own risk.

To get started, launch the Terminal (found in /Applications/Utilities/) and use the following general syntax, replacing level and drive name as appropriate:

diskutil secureErase freespace (level 0-4) /Volumes/(Drive Name)

(level 0-4) is a number indicating the number of passes to write to the free space, ‘freespace’ indicates you are erasing only the free space and not the entire drive itself – a critically important difference – and (Drive Name) is self explanatory. Users can also choose the disk identifier if desired. If you aren’t sure of the name of the drive, using diskutil list will show you all mounted drives and partitions. If the drive in question has a space in the name, you should place it in quotes or escape it with backslashes.

For example, to perform a secure erase with 35 passes on free space on a drive named “Macintosh HD” you could use the following command string:

diskutil secureErase freespace 3 "/Volumes/Macintosh HD"

Hitting return will instantly begin the secure erase of any free space. This is irreversible, so as we’ve mentioned a dozen times already, be sure the syntax is exact.

verbs. Ownership of the affected disk is required.

Level should be one of the following:

o 0 – Single-pass zero-fill erase.

o 1 – Single-pass random-fill erase.

o 2 – US DoD 7-pass secure erase.

o 3 – Gutmann algorithm 35-pass secure erase.

o 4 – US DoE algorithm 3-pass secure erase.

That’s all there is to it, and this is how you can continue to erase free disk space on a Mac running OS X El Capitan or later with the newly limited Disk Utility. Another option is to use an old version of Disk Utility in modern versions of Mac OS X, either from a boot drive or recovery mode, of an older Mac OS release, or with the application itself, but that is generally not recommended.

And yes, this works on both standard hard disk drives with spinning platters, and modern SSD disks, though with an SSD drive the feature is less relevant as TRIM / garbage collection should handle the file removal on it’s own. For SSD volumes, a better option is to enable and use FileVault disk encryption on the Mac, which encrypts data on the drive making it unrecoverable without the FileVault key, thus obviating the need to securely erase free space on the volume.


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Apple Releases Os X El Capitan, Featuring Full

Apple has officially released OS X El Capitan for the Mac, adding some new improvements as well as bringing parity with changes in iOS 9, released two weeks ago. OS X El Capitan (version 10.11), can be installed on any Mac that runs OS X Yosemite: simply download the free update from the Mac App Store. The release does not feature anything radically new — like the major visual overhaul that came last year — but there are new features as well as a strong focus on overall performance and stability improvements.

Here’s what’s new in Apple’s latest version of the Mac operating system …

Spotlight Search

Apple has made some significant to changes to Spotlight, the system search function that pops up in the center of the display when you hit Command+Space. First off, in El Capitan, it doesn’t have to be in the center. As silly as it sounds, you can now freely resize and position the Spotlight box to match your own preferences for the first time. Apple has also bolstered the library of possible search terms to include more transient and informational data, like weather, sports scores or even YouTube and Vimeo video results. You can also make your search queries a lot more casual and Spotlight will understand what you mean. Rather than typing with obtuse filter syntax, you can use natural language queries like ‘email from Joshua last year’ or ‘presentations from last week’. These queries work great, are easy to remember and formulate, and work in apps like Finder and Mail as well as the Spotlight search bar.


Crucially, once you upgrade Notes to use iCloud Drive, El Capitan is required to sync with iOS 9. Yosemite users have no choice but to upgrade their Macs if they want to retain cross-platform harmony. Also keep in mind that sketches can only be created and edited on iOS 9 devices — they are only viewable on OS X.

Safari 9

Matching Chrome from three years ago, Safari 9 adds Pinned Tabs. Essentially, you can put your favorite websites permanently in your URL bar as ‘small buttons’ on the left side of the tab bar. The websites stay loaded, so you can quickly switch to them at any time. Another appreciated addition in Safari 9 is revamped AirPlay support: rather than streaming your entire Mac desktop to the Apple TV, you can stream just specific videos embedded in pages. This doesn’t work on all websites, unfortunately, but popular websites like YouTube are supported.

Full-Screen Split View

A common workflow in El Capitan will be to use the new windowing features to put Safari at about 2/3rds width, with a smaller utility or social networking app filing the rest of the space. This is thanks to the addition of Split View for full-screen apps.

Hold down on the green zoom button on any window to activate Split View. Drag the window to either the left or right side of the screen to snap it as a ‘full screen’ app, even though that name is a bit of a misnomer because it isn’t actually filling the whole width of the screen. You can then choose another full-screen app for the other side of the screen. This now mirrors Split View multitasking on iPad, although you can drag the divider to any arbitrary ratio of content and drag files between windows. It adds a lot more flexibility to workflows and is especially useful on larger-screen iMacs … where having just one app dominate the display was comical. The combined Split View appears as its own space in Mission Control and can be dragged around like a normal full-screen app. Most apps adapt beautifully to the split-screen layout but there are some exceptions; Notes refuses to lose its left-hand column so isn’t really suitable as a skinny-width app unless you’re using a single note window.

It’s also worth noting that the new Mission Control drops window labels and hides desktop previews until you slide your mouse towards the top of the screen, which I personally think is a regression. Text labels show temporarily on hover but you lose the glanceable nature of the old behavior.


Updates to Mail in OS X El Capitan heavily respect the adoption of full screen. In earlier versions of OS X, Mail was not a good Full Screen citizen. Composing a new mail message would open a window outside of the Full Screen space. Yosemite added an integrated compose window and El Capitan builds on this further by adding a tab bar, so you can compose multiple messages at once. Similar to iOS, you can also slide the compose window down to refer to other messages before you finish sending your message.

Performance Improvements

For graphics, Apple has implemented Metal, its high-performance drawing framework, at the core of El Capitan so that it powers all system-level graphics operations. This should provide better frame rates and snappier transitions across the OS — it’s particularly noticeable for the full-screen sliding animation when switching between maximized windows and desktop spaces. Metal is also available to third-party developers, so game creators will be able to use it to push more performance out of the hardware. Apple also claims it has improved the foundations of OS X in other ways to make everything feel faster. The company claims speed improvements from 4x faster PDF rendering to 1.4x faster app launching. Naturally, real-word gains will vary based on a multitude of factors.


Like any operating system update, there’s a bunch of minor improvements and refinements across the system. Following iOS 9 and watchOS, OS X gets the San Fransisco font makeover. There are also minor redesigns to many of the stock interface elements, including some moderate shadowing. It’s personal preference of course, but I think it looks way better than the buttons and controls used in Yosemite. Maps gets Transit directions, Photos finally lets you geotag pictures and supports third-party editing extensions, and there’s even a Find My Friends widget in Notification Center. You can even shake the mouse cursor to enlarge it in case you lose track of what you are doing. There also some welcomed additions for Chinese and Japanese users, including a special system font for Traditional and Simplified Chinese characters (which is apparently better for readability), improved trackpad OCR and as-you-type translation of Hiragana into Japanese.


In summary, El Capitan is not the biggest update in Mac history, but that doesn’t mean there aren’t a variety of changes and improvements to enjoy. It’s expected for a maturing platform to have less major additions and it doesn’t really matter when the updates are free.

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How To Create A Os X El Capitan Boot Installer Usb Flash Drive

Many Mac users like to make a bootable installer drive for installing OS X El Capitan, whether for performing a clean install, or for making it easier to install OS X 10.11 onto multiple Macs. We will walk through creating a bootable install flash drive from OS X El Capitan with the final public version.

Before getting started, know the requirements necessary to make a bootable OS X El Capitan installer drive are as follows:

An 8GB or larger USB Flash Drive like these, this will be formatted and turn into the OS X El Capitan bootable installer

The OS X El Capitan installer application must be on the Mac and in the /Applications/ folder, download OS X El Capitan here if you haven’t done so yet (yes. you can re-download it)

Presumably you have already made the USB flash drive into a Mac compatible format with Disk Utility, if not you can follow the directions here to format a drive for Mac OS X compatibility HFS+.

When you’re ready, plug the USB / flash drive into the Mac with the OS X El Capitan installer application on it.

1: Rename the USB Flash Drive to Become the OS X El Capitan Bootable Installer

The next thing you’ll want to do is rename the target volume that you wish to turn into a bootable installer drive, in this case an external USB flash drive. To avoid any confusion, we’re naming the USB drive to “ElCapInstaller” (without the quotations), though you can name it whatever you want as long as you adjust the command line syntax to match.

You can do this through the Terminal or the Finder as shown above.

2: Make the OS X El Capitan Bootable Installer Drive with a Terminal Command

Launch the Terminal application, found in /Applications/Utilities/ and enter the following command exactly (unless you changed the target volume name from ElCapInstaller to something else) onto a single line, the text will wrap because it is long, but it’s important to have proper syntax:

sudo /Applications/Install OS X El chúng tôi --volume /Volumes/ElCapInstaller --applicationpath /Applications/Install OS X El chúng tôi --nointeraction

Hit the Return key and enter the administrator password when requested.

You’ll then see the following screen text in the Terminal:


The target USB disk or flash drive will be erased first and then copy the files to it so that it will become a bootable OS X El Capitan installer. This can take a while to complete, so wait for the “Done” message before continuing.

When you see “Done”, that’s it, your OS X El Capitan installer drive has been created, it’s bootable, and you can use it to update as many Macs as you want to with OS X 10.11.

To boot from the installer drive, hold down the Option key during Mac system start, and select it from the startup volume menu.

Otherwise, you can insert the installer USB disk / flash drive into any Mac and launch the installer directly from the drive.

Can you show me how to make an Install OS X El Capitan boot drive?

If you want to watch a video walkthrough of the entire process of making an OS X El Capitan bootable installer drive, we’ve got you covered, here it is embedded below for easy viewing:


How To Secure Erase A Mac Ssd / Hard Disk From Recovery Mode

This is very much a workaround, as you’ll technically be erasing the drive twice in the process. The first time will not be the secure erase, it’s the second time formatting that will allow you to achieve the desired outcome. For users with an SSD drive, it’s important to note that using the secure formatting options like 7 pass and 35 pass could potentially lead to a reduction in drive life span, or performance degradation, though TRIM is thought to mitigate that risk. Be sure you understand that and are comfortable with that potential before proceeding.

Secure Format an SSD (or the OS X Boot Disk) via Recovery Mode

The newest Macs ship with a Recovery partition rather than a separate external reinstall disk, and if you’ve ever rebooted a newer Mac, iMac, MacBook Air, or MacBook Pro with an SSD from the Recovery partition to reformat the drive, you may have noticed that by default the “Security Options” button is greyed out in the Disk Utility options, seemingly preventing a standard “secure” erase procedure. The precise reason for this isn’t entirely clear, though some speculate it’s because writing 1’s and 0’s to an SSD can lead to performance degradation and a reduction in the drives lifespan, and that it persists even in the most recent versions of OS X suggests it’s not just a bug. Nonetheless, many users want the option for secure removal of data from the SSD. The most obvious solution to this problem is to boot the Mac from an external boot drive ( here’s how to make one for Mountain Lion ), but that isn’t always an option for everyone, but fortunately there is a workaround that lets you perform a secure erase directly from the Recovery partition chúng tôi is very much a workaround, as you’ll technically be erasing the drive twice in the process. The first time will not be the secure erase, it’s the second time formatting that will allow you to achieve the desired outcome. For users with an SSD drive, it’s important to note that using the secure formatting options like 7 pass and 35 pass could potentially lead to a reduction in drive life span, or performance degradation, though TRIM is thought to mitigate that risk. Be sure you understand that and are comfortable with that potential before proceeding.

Though it may be obvious, it’s important to point out and to remember that this process removes all data from the drive, which then becomes unrecoverable due to the highly secure formatting options. Always back up important data before formatting a drive, or else it will be gone forever.

Reboot the MacBook and hold down the OPTION key, then select the Recovery partition

At the OS X Utilities menu, choose “Disk Utility”

Select the hard drives primary partition (usually called Macintosh HD) from the left, then choose the “Erase” tab

Under “Format” choose “Mac OS Extended (Journaled, Encrypted) – the “Encrypted” part is crucial

Choose “Erase” and set a password for the encrypted partition, for now choose a simple password that’s easy to remember, then choose “Erase”

Let the drive erase and turn into an encrypted format, this process can take a while depending on the drive type, size, and speed

Now select the partition in Disk Utility again, and from the “Erase” tab choose “Mac OS Extended (Journaled)”

Choose “OK” and let the secure erase proceed, when finished you will have a blank primary partition that has been securely formatted

The Macs hard drive has now been securely erased, entirely from the built-in Recovery partition, and without the need of an external boot drive or disk. At this point you may want to repair the disk since you’re already booted into Recovery, or you can exit out of Disk Utility and re-install a clean version of OS X on the Mac if desired, or do whatever else you want with your newly blank hard drive space.

Note, this does not remove the Recovery partition. You can do that separately if desired, but it is not recommended as you will be unable to restore OS X or boot into Recovery mode once it has been removed, thereby requiring the usage of an external boot disk to install Mac OS X back onto the machine.


How To Navigate Mail Messages With The Keyboard In Mac Os X

To use keyboard email navigation in the Mac Mail app, you’ll want to start at the primary double or triple pane primary Inbox screen as if you just opened Mail. The rest is just a matter of using the keyboard rather than the mouse, and making a new habit of that.

Basic Mac Mail App Navigation with Keyboard Shortcuts

Use the Up / Down arrows to navigate to the next or previous email message and open the selected message in the mail panel

Use the Spacebar to scroll down in the selected mail message

Use the Tab key to switch the currently active panel (Search box, Mailboxes, Inbox, Message content

That will allow you to move between the next and previous mail message using just the keyboard, but if you want to start replying to, forwarding, marking as unread, and other common mail activities, you’ll want to use some other keyboard shortcuts.

By the way, if you find the email content text to be either too small or too big, you can change the font size in Mail rather easily.

Of course, navigating between the next and previous message in your inbox is one thing, you’ll likely want to interact with those messages to, which is where the next set of keyboard shortcuts comes in for a variety of tasks in Mail app for Mac OS X.

Other Helpful Mail App Keyboard Tricks for Mac

Hit Command+R to reply to the currently selected message

Hit Command+Shift+D to send an active message, reply, or forward

Hit Command+Shift+U to mark as unread the selected message

Hit Command+N to create a new eMail message

Hit Command+Shift+F to forward the selected message

Hit the Return key to open the selected message into a new window

Use Command+W to close an open message, or the primary message window

Use Command+0 (zero) to return to the message viewing window if you accidentally close it

There are many other keyboard shortcuts for Mail in MacOS X, but these are some of the essentials that are worth remembering without being overloaded with some of the more obscure options. Exploring the Mail menu items will reveal many more, and you can always create a custom keystroke for something if you discover a menu item function that doesn’t yet have an attached keyboard shortcut.

At the moment, the Mail app in Mac OS X does not include a “Next Message” or “Previous Message” keyboard shortcut that is independent of the arrow keys for selecting messages, which can lead to some confusion for users who have turned to the Mail app in Mac OS X as their default email client, particularly if they came to Mail from another email client like MS Outlook or Thunderbird. Note that none of these keyboard shortcuts for moving around Mail are specific to any version of Mac OS X, they’ve been on the Mac for quite some time and therefore will work regardless of the computer running MacOS Mojave, High Sierra, Sierra, El Capitan, Mac OS X Yosemite, Mavericks, Mountain Lion, Snow Leopard, and likely just about any other version too.

Considering that iOS does include a “Next” and “Previous” message button in the Mail app on iPhone and iPad, it wouldn’t be too surprising if such a feature was added to the Mac sometime in the future. In the meantime, use the arrow keys and spacebar trick, it’s effective and makes browsing through a ton of emails quite fast.


Change File Permissions In Mac Os X

You can instantly change file permissions in Mac OS X without getting your hands dirty in the command line by using the Finder instead. All you need to do is access the “Get Info” panel for the file, folder, or application in question. These instructions demonstrate locating the file permissions manager, and how to adjust privileges for items found in Mac OS.

It’s worth mentioning that you can also use this trick to quickly view current file and folder permissions and ownership details in the Mac OS X Finder. To view permissions, just use the Get Info panel as described below but don’t make any modifications. Mac OS X calls permissions “Privileges”, but they mean the same thing.

How to Change File Permissions on Mac

This is the most user friendly way to view or adjust file permissions in Mac OS X, it works with anything found in the Finder file system, be it a file, binary, application, or a folder. Here’s what you’ll want to do:

Select the file or app in the Finder you want to edit permissions for

At the bottom of the Get Info window, you’ll see “Sharing & Permissions”, select the arrow to drop down the options

Adjust permissions* on a per user basis, the options being: read and write, read only, or no access

When finished, just close out of the Get Info window. The changes to permissions happen immediately as you select items from the privilege option dropdown menus.

Permission Types & Explanations of Limitations

The permissions options are fairly self-descriptive in their naming, but here’s a quick overview in case you’re new to the concepts on a file level:

Read & Write: The user can both read the file, and write to the file (make changes, modify the file, delete it, etc)

Read Only: The user can only read the file, and is therefor unable to make changes to the file

No Access: The user has no access to the file at all, meaning the user can not read the file or write to it

When you’re finished setting the desired permissions and privileges, close the Get Info window and the changes will take effect immediately.

Notice that you can’t make files executable through this the Get Info panels, you’ll still need to pull up the terminal for that.

One of our readers pointed out that you can use Get Info to adjust file permissions on remote files using the Mac OS X built-in FTP client, which is pretty convenient if you’re without a separate FTP app but you’re remotely needing to change privileges on something.

Generally speaking, if you’re not sure what to set, you shouldn’t mess around with file permissions since it can change the way a file or application responds to a given document. This is particularly true with system files and applications, as permissions can mean the difference between some apps working and some not. If you’re digging around because of frequent errors regarding access to files or ownership, try using the Recovery Mode method of repairing user permissions that works with Mac OS X 10.7, 10.8, 10.9, 10.10, macOS 10.12, 10.11, 10.13, etc, which can usually sort out those problems automatically without any manual modification of files.

You can also modify permissions from the command line using the ‘chmod’ command followed by flags or sequences and a file name, but that’s really a topic for another article.


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