i've noticed that whenever i get that error, if i click 'info' for the disk image, it is of a format that i can't apply using disk utility. I'm 99% sure the error 254 indicates an incorrect drive format/partition type. Since Unetbootin came out, I pretty much avoid any other method if at all possible. I had to do this because I inadvertently completely jacked the Ubuntu installation on my Eee to the point that I could not recover, and I didn't happen to have a working bootable flash drive for it at that moment). (FWIW, I know I've done this at least once - it's even possible to make a bootable USB of an Intel Linux distribution purely from a PPC Mac. If that's not a possibility, you can use OS X, and follow tutorials appropriate to your distribution, such as the ones at, but you'll have to find an alternative way to put a bootable MBR on it and syslinux it.

Unetbootin is an automated tool that will take many different ISOs (it isn't guaranteed to work if you use it with an ISO that isn't on its approved list, though, so you might want to check the compatibility first) and makes bootable flash drives off them.īut there is no OS X version of it, AFAIK, so the USB must be created using unetbootin in a Windows or Linux environment. The core problem is that how an ISO is converted into bootable USB is not the same from one distribution to another. Using any other method to copy the ISO contents also doesn't work.īoth are true for any distribution of Linux.

(This note is in case you've updated from Lion.- Using dd to write the ISO contents directly to the USB absolutely does not work. Please note: This is for OS X Lion users only, this no longer works the same way on OS X El Capitan.

Ensure that the 'Verify burned data' checkbox is ticked (you may need to click on the disclosure triangle to see the checkbox).

iso file, and click on the 'Burn' button in the toolbar. iso file to the left pane in Disk Utility.

Launch 'Disk Utility' (Applications → Utilities → Disk Utility).

If you’re using an older version of Mac OS X, you might not have the Disk Utility application. The easiest way to burn an ISO, the file you need to install Ubuntu from a CD, is by using Disk Utility. Please note: This is for OS X Lion users only

Mac os x burn iso to usb