Encrypt and protect a storage device with a password in Disk Utility on Mac. When you format an internal or external storage device, you can encrypt and protect it with a password. If you encrypt an internal device, you must enter a password to access the device and its information. If you encrypt an external device, you must enter the password when you connect the device to your computer.
Even though Mac computers are capable of reading hard drives that are formatted for Windows, if you intend on using your external HDD as a bootable disk or want to use it to backup files with your Mac’s Time Machine, you must format it to be entirely Mac compatible.
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Easily store and access 1TB to content on the go with the Seagate Portable Drive, a USB external hard drive Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop. Reformatting may be required for Mac. Close the external hard drive once all files moved to from mac to external hard drive. Using Disk Utility To Transfer Files Mac To External Hard Drive. Sometimes your external hard drive doesn’t allow you to transfer files from Mac. Because it’s your hard drive may be formatted with NTFS which is normal in a windows environment. Nowadays, several people who are using the external hard drive, having trouble while connecting them with Mac. Even a few days ago, I got the same issue while attaching an external hard drive with my mac book pro, such as 'the disk you inserted was not readable by this computer.'
To make a Mac act as an external hard disk, you can put it in TargetDisk Mode and connect it to another Mac with a FireWire orThunderbolt cable, as follows:
Note: Target Disk Mode is available on most recentMacs; however, computers that do not have FireWire or Thunderboltports are excluded.
Shut down the computer you want to use as an external hard disk(i.e., the target computer). If you are using a portable computer,make sure it is running on AC power. You don't need to power downthe other computer (i.e., the host computer).
Connect the FireWire or Thunderbolt cable to the correspondingport of the target computer, and then connect the other end of thecable to the host computer's port.Note: If the computers have different kinds of ports(e.g., one has a FireWire 400 port while the other has a FireWire 800or Thunderbolt port), you will also need one or more adapters.
Start up the target computer and hold down the lettert on its keyboard. Its drive will spin up, andits icon should appear on the host computer. The target computer'sdisplay will show a moving icon.
Alternatively, you can do the following:
From the Apple menu, select System Preferences....
In System Preferences, from the View menu, selectStartup Disk.
In the Startup Disk preference pane, click Target Disk Mode....
To exit Target Disk Mode, on the host computer, eject thetarget computer's disk, and then shut down thetarget computer. Disconnect the cable, and then start up thetarget computer; it will boot normally.
Disk Utility User Guide
When you format an internal or external storage device, you can encrypt and protect it with a password. If you encrypt an internal device, you must enter a password to access the device and its information. If you encrypt an external device, you must enter the password when you connect the device to your computer.
Important: If you encrypt an external storage device, you can’t connect it to an AirPort base station for Time Machine backups.
To encrypt and protect the device with a password using Disk Utility, you must erase the device first. If the device contains files you want to save, be sure to copy them to another storage device or volume.
If the device contains any files you want to save, copy them to another storage device or volume.
In the Disk Utility app on your Mac, choose View > Show All Devices.
In the sidebar, select the storage device you want to encrypt.
Click the Erase button in the toolbar.
Enter a name for the volume.
Click the Scheme pop-up menu, then choose GUID Partition Map.
Click the Format pop-up menu, then choose an encrypted file system format.
Enter and verify a password, then click Choose.
To change the password later, select the volume in the sidebar, then choose File > Change Password.
(Optional) If available, click Security Options, use the slider to choose how many times to write over the erased data, then click OK.
Secure erase options are available only for some types of storage devices. If the Security Options button is not available, you can’t use Disk Utility to perform a secure erase on the storage device.
Writing over the data three times meets the U.S. Department of Energy standard for securely erasing magnetic media. Writing over the data seven times meets the U.S. Department of Defense 5220-22-M standard.
Click Erase, then click Done.
You can encrypt your data without erasing it by turning on FileVault in the Security & Privacy pane of System Preferences (see Encrypt Mac data with FileVault).
You can also encrypt a disk and protect it with a password without erasing it. See Encrypt disks or memory cards to protect your Mac information.
Hard Disk External For Mac Os
See alsoErase and reformat a storage device in Disk Utility on MacPartition a physical disk in Disk Utility on Mac