I am trying to install clear os on external usb hdd connected to lenovo laptop with windows 7 and ubuntu 16.04 dual booting working. I have used neosmart to boot ubuntu as grub does nto detect windows. this is not my question. Both windows 7 and ubuntu are working well. But i am unable to custom partition external hdd to install clearos. Ext. Hdd is 680 gb capacity with 4 partitions made. I use them for data. I want install on one of the partions. while custom partitioning, i get error
"unable to allocate free space"
after i allocate space to /boot.
Can anybody tell me step by step partitioning. I am not expert in linux. i have done couple of installations of dual booting linux and windows.
Pls help me