Why can't 12.04 installer see one of my hard drives

Question

I'm trying to install Ubuntu 12.04 32-bit from a USB pen drive. I have two drives, a WD Caviar Black and a Samsung SPC250.

At the "installation type" stage, it only sees my Samsung and the USB pen drive, not the WD.

• I checked the drive with gparted and everything seems fine.
• I tried the alternate installer but that doesn't work either
• I tried changing from IDE to AHCI in the BIOS and back

What can I do now?

1st picture, g.parted shows WD disk as sda. But ubiquity can't see.Only my second drive as sdb.Even i reserved space as ext4 for installation. 2nd picture,you can see 1tb sda disk. But it unable to mount.

I want to install ubuntu to sda disk.

Thanks for help.

Answer 1

Would you please clarify what you mean when you say only your Samsung and your USB (install) drive are available at the Installation Type stage?

Have you selected Something Else in the first Installation Type window and then pressed the Continue button to display the window which allows you to do your own partitioning as shown in the example screenshot below?

If you've reached the partitioning window (below) have you scrolled the list and it only has entries for two drives? But if you start gparted after booting your install USB and choosing Try Ubuntu, then all three drives are shown?