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UNetbootin for Mac OS X can be used to automate the process of extracting the Ubuntu ISO file to USB, and making the USB drive bootable. The resulting USB drive, however, can be booted on PCs only. If attempting to make a USB drive that can be booted from a Mac, follow the instructions below.
How to install rEFIt on an external USB drive. Download rEFIt from here. In most cases, the IDENTIFIER for your USB flash drive is something else.
We would encourage Mac users to download Ubuntu Desktop Edition by burning a CD for the time being. But if you would prefer to use a USB, please follow the instructions below.
Note: this procedure requires an .img file that you will be required to create from the .iso file you download.
TIP: Drag and Drop a file from Finder to Terminal to 'paste' the full path without typing and risking type errors.
- Download the desired file
- Open the Terminal (in /Applications/Utilities/ or query Terminal in Spotlight)
- Convert the .iso file to .img using the convert option of hdiutil
- Note: OS X tends to put the .dmg ending on the output file automatically.
- Run to get the current list of devices
- Insert your flash media
- Run again and determine the device node assigned to your flash media (e.g. /dev/disk2)
- Run(replace N with the disk number from the last command; in the previous example, N would be 2)
- If you see the error 'Unmount of diskN failed: at least one volume could not be unmounted', start Disk Utility.app and unmount the volume (don't eject).
- Execute (replace /path/to/downloaded.img with the path where the image file is located; for example, ./ubuntu.img or ./ubuntu.dmg).
- Using /dev/rdisk instead of /dev/disk may be faster.
- If you see the error dd: Invalid number '1m', you are using GNU dd. Use the same command but replace bs=1m with bs=1M.
- If you see the error dd: /dev/diskN: Resource busy, make sure the disk is not in use. Start Disk Utility.app and unmount the volume (don't eject).
- Run and remove your flash media when the command completes
- Restart your Mac and press alt while the Mac is restarting to choose the USB-Stick
Please notice: While all of the info and above commands are executed properly on a MacBook Air 3,2 (that is the 2010 version 13' version of the Air) the end result will not produce a bootable USB device, at least not with the image for Ubuntu 10.10 64-bit. When booting of the USB device the following message or something similar will appear: 'Missing operating system' and the process is auto-magically halted.
To get the USB device (e.g. a USB stick) to show up at all in the boot menu you also may have to reboot/turn on/off the computer a couple of times and also resync the partition tables using rEFIt. After doing this the USB should then appear as a bootable device while holding in the alt or c key when you are rebooting the computer. Notice that both the computers built in bootloader and rEFIt will identify the USB device as a Windows device, but that's not a problem and expected.
A workaround to the-usb-device-is-not-booting-problem is to:
- Install rEFIt.
- Create a bootable start disk using Ubuntu and a USB stick.
- Create a separate partition on the Airs HD.
- dd the whole USB stick to that partition.
- Resync with rEFIt. Turn power off and on.
- Select Pingo/Windows logo: Install should start. (Here you might want to press F6 to change parameters, e.g. use nomodeset)
Alternatively, burning a CD and installing via an external CD-drive will work fine on the Macbook Air 3,2.
(Moved from Installation/FromUSBStick)
We would encourage Mac users to download Ubuntu Desktop Edition by burning a CD for the time being. But if you would prefer to use a USB, please follow the instructions below. Note: this procedure requires an .img file that you will be required to create from the .iso file you download. TIP: Drag and Drop a file from Finder to Terminal to 'paste' the full path without typing and risking type errors.
- Download the desired file
- Open the Terminal (in /Applications/Utilities/ or query Terminal in Spotlight)
- Convert the .iso file to .img using the convert option of hdiutil (e.g., hdiutil convert -format UDRW -o ~/path/to/target.img ~/path/to/ubuntu.iso)
Note: OS X tends to put the .dmg ending on the output file automatically.
- Run diskutil list to get the current list of devices
- Insert your flash media
- Run diskutil list again and determine the device node assigned to your flash media (e.g., /dev/disk2)
- Run diskutil unmountDisk /dev/diskN (replace N with the disk number from the last command; in the previous example, N would be 2)
- Execute sudo dd if=/path/to/downloaded.img of=/dev/rdiskN bs=1m (replace /path/to/downloaded.img with the path where the image file is located; for example, ./ubuntu.img or ./ubuntu.dmg).
- Using /dev/rdisk instead of /dev/disk may be faster.
- If you see the error dd: Invalid number '1m', you are using GNU dd. Use the same command but replace bs=1m with bs=1M.
- If you see the error dd: /dev/diskN: Resource busy, make sure the disk is not in use. Start the 'Disk Utility.app' and unmount (don't eject) the drive.
- Run diskutil eject /dev/diskN and remove your flash media when the command completes
- Restart your Mac and press Alt while the Mac is restarting to choose the USB-Stick
Tips
By Malcolm Owen
Wednesday, October 09, 2019, 01:39 pm PT (04:39 pm ET)
If you have more than one Mac you want to upgrade to macOS 10.15 Catalina but don't want to waste so much bandwidth downloading it for each machine, one option is to create a bootable installer on a spare USB flash drive. Here's how to do it with the Terminal.Wednesday, October 09, 2019, 01:39 pm PT (04:39 pm ET)
One of the problems with the release of a major operating system update like macOS Catalina is the amount of times it has to be downloaded. As Apple usually intends each Mac or MacBook needing to be updated to download it, the process isn't really efficient enough for instances where many Mac desktops need the upgrade, like in a school or business if there isn't device management or macOS Content Caching for whatever the reason.
The strain could also be felt by users who own multiple Macs but also have a limited data allowance from their Internet provider, or a small amount of bandwidth that could make updating multiple machines take a very long time and saturate the available connection.
While in the olden days it was possible to get the software update on physical media, Apple doesn't offer that option anymore. However, it is still possible to create your own media, such as a spare USB thumb drive, that can do the same job.
Acquiring the Installer
The first hurdle is to actually get the macOS Catalina installer onto a Mac. This is an unavoidable part of the process and will require just over 8 gigabytes of drive capacity to store.
Go to the Mac App Store and search for Catalina using the search bar, then click on View next to the macOS Catalina listing. Alternately, open the Mac App Store Preview page for macOS Catalina here then select View in Mac App Store.
Click on Get. This will load up the Software Update utility, which will ask if you want to download macOS Catalina. Click Download.
After the download has finished, macOS will automatically start the installer. Press Command-Q to quit the installer before it continues, as the update will be deleted upon installation.
Creating the Bootable Drive
You need an external drive to turn into a bootable version, and since it needs to be portable, your best choice is a USB thumb drive with a capacity of 16GB or more. Be aware that the drive will be wiped as part of the process, so ensure there isn't any precious data on the drive that could be lost if it isn't backed up elsewhere.
Connect the external drive to your Mac, and make a note of the external drive's name as it appears within macOS. This is important, as using the wrong name could lead to another connected drive being wiped by mistake.
Open Terminal within the Utilities folder within the Applications folder and enter in the following command by copying and pasting it directly into the window. Make sure to change the element titled 'USBdrive' for the name of the drive you intend to become the bootable installer.
sudo /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia—volume /Volumes/USBdrive —/Applications/Install macOS Catalina.app
Once pasted and corrected, press enter, then enter your password for macOS and press enter again.
Terminal will then warn of the USB drive being wiped as part of the process. Type 'Y' and press enter. Leave the Mac alone as it formats and copies over the installer.
Once Terminal says 'Install media now available,' it is safe to right-click the removable drive on the desktop renamed 'Install macOS Catalina' and select the 'Eject' command. It is now safe to remove the drive from the Mac.
Upgrading another Mac
![Boot Boot](http://wheelsandbytes.github.io/comp/install-refit/resources/768E14177194FF140987DAAF8585024B.jpg)
Before proceeding, ensure there are adequate backups available for the Mac you are about to upgrade before the process starts.
With the target Mac you want to upgrade turned off, connect your external drive. When turning on the Mac, hold down the Option key on the connected keyboard to bring up the Startup Manager.
The Startup Manager is used to boot from a different drive from the default. In this case, select 'Install macOS Catalina.'
The Mac will then bring up a macOS Utilities window. To perform a straight update, select 'Install macOS' and follow the prompts.
The macOS Utilities menu also allows you to erase the Mac's drive, which you can optionally do if you do not wish to save any of the data and want a completely clean slate for the installation.