Now I´m unable to use the external disk, it appers on the desktop but I cannot eject it (because the computer says the disk is being used) I cannot repair it or erase it using disk utility because an error appears: unable to unmount. A different solution would be to try to access the data from a PC, to extract your files from the Time Machine Backup, to put it on a drive that can be accessed from your iPad and to transfer the data afterwards. Same problem with both external drives, which have different manufacturers. If the iPad is able to see the hard disk, it might be able to deliver similar results, but I do not have any idea if that works. Then: The disk wasn’t ejected because one or more programs may be using it. When Time Machine is done, as is apparent from the icon in the menu and from the Time Machine Preferences pane.
as well as directly make ISO files from your CD/DVD-ROM or hard disk. Time Machine runs, and is the only application to use the disk. Tip Some external hard disk drives can draw their power from your computer via. For x86 architecture you can burn the ISO directly into a USB drive using etcher. At this point the Backup Disk is selected and the next Time Machine Backup will start in 120 Seconds. Select a drive and click on the Use Disk button. A window opens showing External Storage Drives connected to your Mac. I tried to use my WD 320gb disk with time machine, while the information was being recorded my lapton run out of power and shut down. After a moment, the disc icon appears in the toplevel computer window. To open System Preferences - Click on the Apple icon > System Preferences.