When upgrading Ubuntu from 11.10 to 12.04 I discovered an unexpected problem. The upgrade was stopped because there wasn't enough free space for the installation. I managed to free some space and do the upgrade but now a prompt appears after logging in saying I'm out of space. This prompt asks me if I want to examine the problem. The "Disk Usage Analyser" is opened. In the top it says:

Total filesystem capacity: 47.0 GB (used: 13.5 GB available: 33.4 GB)

Folder -- Usage -- Size

• / -- 100% -- 12.5 GB
• • usr -- 44.8 % -- 5.6 GB
• • home -- 30.3 % -- 3.8 GB
• • lib -- 13.0 % -- 1.6 GB
• • var -- 9.1 % -- 1.1 GB
• • boot 2.5 % 309.5 GB
• • and a lot of small contributors like: etc, opt, sbin, bin etc.

I do not really understand this problem since the analyser in the top says that I have 33.4 GB left in this file system. What can I do to make Ubuntu use the remaining space?

Running df -i in the terminal gives:

Filesystem      Inodes  IUsed   IFree IUse% Mounted on
/dev/sda7       610800 576874   33926   95% /
udev            213451    563  212888    1% /dev
tmpfs           218524    486  218038    1% /run
none            218524      3  218521    1% /run/lock
none            218524      7  218517    1% /run/shm
/dev/sda8      2264752  16371 2248381    1% /home

The output of df -h

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda7       9,3G  7,8G  1,1G  88% /
udev            993M  4,0K  993M   1% /dev
tmpfs           401M  884K  400M   1% /run
none            5,0M     0  5,0M   0% /run/lock
none           1003M  152K 1002M   1% /run/shm
/dev/sda8        35G  4,0G   29G  13% /home
/dev/sda2       101G   64G   37G  64% /media/A2C8E28BC8E25CD3

Running sudo fdisk -l gives

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000080

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1              63       96389       48163+  de  Dell Utility
/dev/sda2   *       98304   210434488   105168092+   7  HPFS/NTFS/exFAT
/dev/sda3       210436094   312576704    51070305+   f  W95 Ext'd (LBA)
/dev/sda5       306279288   312576704     3148708+  dd  Unknown
/dev/sda6       210436096   214341631     1952768   82  Linux swap / Solaris
/dev/sda7       214343680   233873407     9764864   83  Linux
/dev/sda8       233875456   306278399    36201472   83  Linux

Partition table entries are not in disk order