So you've added space to a VM but Ubuntu still shows the old size? The partition was created with a certain size, so that new space will just be unallocated until you add it to a partition. You could just add a new partition, but chances are you want the root partition to be bigger, yes?
Before proceeding, realize that there is a very real possibility that you will lose data if you mess this up. Still here? Cool.
- You will need to reboot
- I have not tested this with partitions "after" the one I am resizing. There was a swap partition, but I unswapped and deleted it.:
- If I had to guess, I would say that this would not work if you had any partitions after the one you are resizing
- This guide comes with no warranty. If you do this and you lose data, don't come crying to me.
Use fdisk to first delete the partition and then recreate it with a larger size.
$ sudo fdisk /dev/sda
Command (m for help): p
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 9437183 4717568 83 Linux
Command (m for help): d
Selected partition 1
Command (m for help): p
Device Boot Start End Blocks Id System
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4, default 1): 1
First sector (2048-10485759, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-10485759, default 10485759):
Using default value 10485759
Command (m for help): p
Device Boot Start End Blocks Id System
/dev/sda1 2048 10485759 5241856 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Note in the above example that the starting position of the new partition is the same as the one we deleted. THIS IS CRITICAL! IF YOU DO NOT DO THAT, YOU WILL LOSE DATA!
To be on the safe side, you'll likely want to also use the a command to add the boot flag to this newly-created partition.
Don't forget to hit w to write the parition table again.
The safest thing to do here is reboot. Hold your breath. Say a little prayer.
Still not done... if you do df you'll still see the old size.
The final step will resize the ext filesystem to the size of the partition
sudo resize2fs /dev/sda1
If all is well, you'll now have a big ol' partition to fill up with cat gifs or whatever.