What is the safest method for repartitioning space from the / partition? [closed]

Question

I've got a 240GB SSD that I'm using as my boot/applications drive and only have Ubuntu 14.04 installed, so no finagling with Windows or OS X installs.

I originally partitioned off 40GB of that 240GB as a fast access area - which I figured would be enough for simple projects now and again.

However, I'm finding that 40GB isn't really enough for everything I want to be able to speedily start (VMs & video/picture editing.)

I ran df -h to see what's being used with what I've installed thus far, and under 15GB of that 200GB of space is actually being used:

$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda3       184G  9.1G  165G   6% /               <--
none            4.0K     0  4.0K   0% /sys/fs/cgroup    |
udev            3.9G  4.0K  3.9G   1% /dev              |
tmpfs           793M  1.6M  792M   1% /run              | All SSD (/ is mounted on SSD)
none            5.0M     0  5.0M   0% /run/lock         | 
none            3.9G  1.6M  3.9G   1% /run/shm          |
none            100M   52K  100M   1% /run/user         |
/dev/sda1        93M  3.4M   90M   4% /boot/efi       <--
/dev/sdb2       914G  124G  743G  15% /home
/dev/sda2        37G   25G  9.8G  72% /media/nate/05b2dfb9-a2ad-4c21-98d3-9c8467a7f4c0
 ^- 40GB partitioned off

Obviously, since so little is being used, I'd like to be able to take some of that space that isn't being used, and put it to work.

According to this q/a the minimum required for / is 8GB, while the suggested is at least 15GB.

Judging by that, could I partition off 100GB of the 200GB currently partitioned and expand the general speedy space by that much?

What I want to know is, how much should I leave partitioned off for / (on /dev/sda3/) and how much can I safely expand the /dev/sda2 partition by so as to have more general speedy space?

The way I originally installed was I set up a 200GB partition for / on the SSD and set up /home/ to be on my 1TB HDD.

And, upon deciding how much is safe to partition off, what would be the safest method for taking that space and adding it to the general speedy space partition?

Answer 1

A couple things:

1. Using LVM to manage your partitions makes it MUCH easier to do this kind of thing.
2. It is a lot easier to increase a partition's size than to decrease it. Especially the root mount.
3. Since all the partitions you're discussing are on the same physical disk, there is no performance benefit from splitting them up into different partitions.

Given the above, you might as well just move the /mnt/media folder directly under the system root. That will get you the extra space. From there, repurpose the "/dev/sda2" parition as you see fit (e.g. using it as a mount /var or /usr).

I would normally suggest using the space from "/dev/sda2" to increase the size of "/dev/sda3", but that would be somewhat difficult in your case. Your SSD's partitions look to be in the wrong order to allow you to just delete the 40GB mount and add that space to the root partition easily (again, using LVM would avoid this issue).

If you aren't afraid of doing some repartitioning via boot disk, then you can get it sorted out. This should get you started, but it's probably more effort than it's worth (unless you're just looking to gain knowledge).