In my machine, there is one SSD 512GB with Raid On mode which Windows 10 is installed. And one hard drive 2TB (divided into three parts, 250GB (Ubuntu 18.4 which is already installed), 250GB (Ubuntu 16.4 which is going be installed), and the rest for other data), which have already installed Ubuntu 18.4, and now due to some problem which some software, not supporting Ubuntu 18.4 yet, so I need to install Ubuntu 16.4.

But when I was installing Ubuntu 18.4, everything was OK, and now when I want to install Ubuntu 16.4, it is not detecting the hard drive.

What can be the reason?

Note: I don't want to install this on SSD HD.


You need to first reboot your system with Ubuntu 16.04 USB stick in live mode. Then open the disk utility app in your Ubuntu 16.04 and check if your hard disk is visible there or not (you will most probably found it there), if not then try to refresh a couple of time and see if your hard disk is listed. Also, try the following command :

$fdisk -l

This will list all the partitions on your hard disk. From there select the required partition and try to format and repartition it into a single drive. Try the following command :

$fdisk /dev/sda

then in the command mode use 'p' to list all the partitions and then select the one which you want to format and format it using 'd' followed by the partition number in the command line. After deleting create a new partition using 'n'. (view the following link for a detailed process: https://www.howtogeek.com/106873/how-to-use-fdisk-to-manage-partitions-on-linux/ )

Once you find your hard disk listed, unmount it once and then again mount it and then start the Installation process normally in live mode.

If the above methods are not helping you then it might be a corrupted USB stick or Ubuntu image file, try rebooting the Ubuntu on the stick with "USB universal installer" or some other software and then try installing Ubuntu on your system OR try downloading the Ubuntu image once again.

Also, make sure you have created some unallocated space in your previously installed system to allocate that memory to the Ubuntu OS.

"GParted is a good partitioning tool which could be used for checking your hard disk and partitioning it." I hope this helps you.

  • Thanks for the reply! I have tried your suggestions, but it only lists the USB drive, still cannot access the HD (2TB). It seems that it completely does not have the permission or something else problem to access the hard drives. If cannot access the SSD, it is OK, no problem, because it is not AHCI mode, but the 2TB hard drive is ready to be accessed from Ubuntu as the 18.4 version did. So...? – Bahramdun Adil Jan 11 at 5:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.