Expand HD Partition in Lion on New Drive

Question

I have a new disk drive in my macbook. It is running lion.  It is a 500 GB drive. My old drive was 160GB.  The new drive boots as the HD drive but only uses 159 GB. I have tried to expand it to 500GB in Disk utility but it will not let me and just goes back to 159GB. I can add a 340 GB partition but I want it all together.
How can I expand HD so that it uses the entire 500GB? 
Any help is much appreciated.

Answer 1

You can expand it, the question is what you can accomplish with repartitioning the drive.
To resize the drive do the following:
1. Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
After the main menu appears select Disk Utility and click on the Continue button. Select the hard drive's main entry then click on the Partition tab in the DU main window.
2. You should see the graphical sizing window showing the existing partitions. A portion may appear as a blue rectangle representing the used space on a partition.
3. In the lower right corner of the sizing rectangle for each partition is a resizing gadget. Select it with the mouse and move the bottom of the rectangle downwards to fill the gray space all the way to the bottom. Click on the Apply button and wait until the process has completed.  (Note: You can only make a partition smaller in order to create new free space.)
It would be wise to have a backup of your current system as resizing is not necessarily free of risk for data loss.  Your drive must have sufficient contiguous free space for this process to work.
If this doesn't work then add a new partition in the gray area. Once you've added a second partition try deleting the new partition, then extend old partition.
One probable reason this may not work is that in installing Lion the Recovery HD has been placed at the end of your existing volume. While the Recovery HD partition is there you cannot extend the partition. So, the best thing to do in this case is to boot from the Recovery HD, repartition the drive into a single partition of 500 GBs and let Disk Utility relocate the Recovery HD. Of course you will have to reinstall Lion:
Install or Reinstall Lion from Scratch
If possible backup your files to an external drive or second internal drive.
Boot to the Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Repartition the hard drive:
1.  Select Disk Utility from the main menu and click on the Continue button.
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area.  If it does not say "Verified" then the drive is failing or has failed and will need replacing.  SMART info will not be reported  on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.
Reinstall Lion: Select Reinstall Lion and click on the Install button.
Note: You can also re-download the Lion installer by opening the App Store application. Hold down the OPTION key and click on the Purchases icon in the toolbar. You should now see an active Install button to the right of your Lion purchase entry. There are situations in which this will not work. For example, if you are already booted into the Lion you originally purchased with your Apple ID or if an instance of the Lion installer is located anywhere on your computer.