Grub can see HDD, but Ubuntu can't

Question

I have a problem. I have 2 Sata HDD's, I can boot Ubuntu, bet it can't see my other hdd. When i boot Grub it shows Mac OS (other hdd).

What's the problem?

Thanks.

Answer 1

Ubuntu has (as far as I know) support for the OSX filesystem, HFS+. Try disabling Journaling;

(Source)

By default, Mac OS X formats volumes in journaled HFS+ volumes.
Journaling is a feature that improves data reliability, and unfortunately it
makes HFS drives read-only in Linux. To disable journaling, just boot into 
OS X and fire up Disk Utility. Click on your HFS partition, hold the Option
key, and click File in the menu bar. A new option to Disable Journaling will 
come up in the menu. Click that, and reboot into Linux. You should have read
and write access to your HFS partition—however, the permissions on your Mac
user's home folder will prevent you from reading or writing those files.

Check out the full article to get around the permission problems.

Answer 2

In what way can't Ubuntu 'see' your drive? You don't see it in your filesystem, or you can't find it using sudo fdisk -l?

It sounds to me like the drive needs to be mounted.

sudo fdisk -l

See how the drive is called, i.e. /dev/sda1 for the partition you want to mount.

sudo mkdir /mnt/sda1
sudo mount /dev/sda1 /mnt/sda1

If fdisk cannot see it, something else is going wrong. (which seems unlikely, since as noted above, Ubuntu should be able to read the HFS file system)