ELI5: Resizing Partitions

Question

I'm really new to linux and servers. I don't really understand the talk in other threads and some say you cannot do it while ubuntu is online while some say you can.

So can someone explain the process to me like I'm 5?

Filesystem     Type      Size  Used Avail Use% Mounted on
/dev/root      ext4       20G  2.4G   16G  13% /
devtmpfs       devtmpfs   16G  4.0K   16G   1% /dev
none           tmpfs     4.0K     0  4.0K   0% /sys/fs/cgroup
none           tmpfs     3.2G  636K  3.2G   1% /run
none           tmpfs     5.0M     0  5.0M   0% /run/lock
none           tmpfs      16G   24K   16G   1% /run/shm
none           tmpfs     100M     0  100M   0% /run/user
/dev/md2       ext4       91G   56G   31G  65% /home

I want to allocate some space from root to md2 (~15G)

EDIT/Note: I do not have physical access to the server and I'm running it command-line with PuTTy

Answer 1

You're best bet is to install gparted. It's available in the ubuntu software center.

In simple terms, yes - you can resize while in ubuntu, BUT sometimes ubuntu handles it's harddrive in a funny way which makes it harder (LVM). If you are using LVM (unlikely), then I would try resizing until you understand a bit more about ubuntu and partitions.

The other situation where you can't resize, is if you're moving the operating system files by resizing. In this case just create a live usb and use gparted while booting from there