We do not support overriding /etc/fstab drives in the GUI, since that can seriously damage your system (if you change the Ubuntu root partition, etc.). If you want to manipulate non-Ubuntu partitions (such as spare Windows partitions), then don't put them into /etc/fstab.
We do not support overriding /etc/fstab drives in the GUI, since that can seriously damage your system (if you change the Ubuntu root partition, etc.). If you want to manipulate non-Ubuntu partitions (such as spare Windows partitions), then don't put them into /etc/fstab.