Ubuntu low disk space on Filesystem root. How to resize root or delete files?

When I first installed Ubuntu (actually ElementaryOS) I didn't think that it would take up that much space, so I made the OS partition 15GB and /home 100GB. sda5 and sda6 are my Linux partitions.

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 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: 0x1b518505 Device Boot Start End Blocks Id System
/dev/sda1 * 2048 823295 410624 7 HPFS/NTFS/exFAT
/dev/sda2 823296 410943487 205060096 7 HPFS/NTFS/exFAT
/dev/sda3 410943488 738621439 163838976 7 HPFS/NTFS/exFAT
/dev/sda4 738623486 976771071 119073793 5 Extended
/dev/sda5 738623488 767918079 14647296 83 Linux
/dev/sda6 767920128 976771071 104425472 83 Linux

The thing is, I don't actually have anything new installed on the OS now compared to when it was fresh. Just a browser and sublime text. Over time, installing system updates, the size just keeps on going up and up.

/usr/src has 2.2 GB of folders named linux-headers-X.XX.X-XX

/lib/modules has 3.9 GB of X.XX.X-XX-generic folders

Advice on what to do would be appreciated.

• If I choose to increase the size of the 15GB partition, how do I do it?
• What are /usr/src and /lib/modules and how do I delete them safely?

1 Answer

It seems like there is a connection between the various aspects to your question.

• /usr/src is a location for source code for installed packages.
• /lib/modules is a location for kernel modules.
• linux-headers-X.XX.X-XX are the header files for your installed kernel(s). Header files are used when you wish to compile a kernel module for your specific kernel. Many common pieces of software compile kernel modules, like Virtualbox, lm-sensors, etc. seehere for some more detailed discussion of exactly how they manifest. I always install the kernel headers and thebuild-essential package when setting up a new desktop, as I usually end up needing it at some point (I don't for servers though, compilers can be a security risk).

So, this all leads me to believe that you have more than one kernel installed, which is a pretty common problem. Its not a bad idea to keep one version back, especially right after an upgrade, but they are large, and can pile up.

Even if you have only one Kernel, You do not need the headers except when installing something that requires compilation against the kernel, so you can always uninstall the packages from Synaptic or software center.

if you have multiple old kernels still installed, you can usually remove them with sudo apt-get autoremove or review the options here for your system. In addition to clearing the kernels, and the header source files, this will also remove the old kernel's modules, stored in /lib/modules

15GB is usually more than sufficient for a root partition, and resizing partitions is a tricky proposition, but it is definitely possible. I strongly recommend you consult this documentation to review your situation, and plan the operation. it will involve shrinking /home, moving it to the right, and finally extending the /.