How to connect and safely unmount a hard drive disk with iFile, Nov 2014
A USB hub from D-Link is recommended, to enable connection to your iDevice.
To wipe and format a drive or partition to HFS+, or fat32, you can use 'gparted', booting a PC with the application from a CD or USB.
If you have an issue unmounting, or a corrupt disk that won't reconnect, resolve by applying the 'check' function, in gparted, by selecting from a right click on the partition. This will repair the drive with no data loss, and takes seconds once you know the process.
In iFile, if you receive the message, 'unmount not successful', there are a couple of sure ways to get around this.
One is to click on the drive in the left panel, then go up one, by pressing 'mnt' at the top.
In the main section, to see the info box, select the 'i', on the mount in question, and wait for the app to scan all the files. Once the scan is complete, try to unmount, using the button at the bottom of the info screen, as opposed to the eject button in the left panel.
If this still doesn't work. Don't disconnect, but close iFile, from iPads multitask app viewer, then when you reopen iFile, the restart seems to stop the processes preventing the unmount, so then try again to unmount, either by the conventional way, with the eject button in the let panel, or the 'unmount' option in 'i'.
If the drive disappears from the left panel at any stage, wait maybe 30-60 secs for it to reconnect, as it often will.
If while writing/copying to a drive, you get the error message, 'file exists', the drive could disappear and and may not reconnect, so will end up corrupted if you disconnect without unmounting, but in this case, refer to the instructions at the top of this page. Also setting the file permissions may help, by selecting the circled 'i' opposite the drive in question, and choosing 'root and wheel', for ownership, and tick 'read, write, and execute', in file permissions, then toggle the 'apply hierarchy' switch above, and click off the 'i' / info window to perform the action.
Hope this helps!