Repartition a Debian Digital Ocean Droplet

1. Create a Droplet

For this example, I made a small droplet running Debian 8.1 x64.  These instructions may work for older Debian versions, and might work for Ubuntu.  You may need to use some other method to boot a live environment than the Grml package I used.

https://www.digitalocean.com/community/tutorials/how-to-create-your-first-digitalocean-droplet-virtual-server

On first boot, you can see that we have a 20GB disk (/dev/vda) as a single Linux partition:

root@debian:~# fdisk -l /dev/vda
 Disk /dev/vda: 20 GiB, 21474836480 bytes, 41943040 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
 Disklabel type: dos
 Disk identifier: 0x4e0e3620

Device     Boot Start      End  Sectors Size Id Type
/dev/vda1  *     2048 41935724 41933677  20G 83 Linux

2. Install GRML RescueBoot

It’s a two step process, first install the grml-rescueboot debian package, then download the grml iso to /boot/grml/ with wget:

root@debian:~# apt-get install grml-rescueboot
root@debian:~# wget http://download.grml.org/grml64-small_2014.11.iso
root@debian:~# update-grub
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.16.0-4-amd64
Found initrd image: /boot/initrd.img-3.16.0-4-amd64
Found Grml ISO image: /boot/grml/grml64-small_2014.11.iso
done

3. Boot from GRML

The default boot option mounts the vda device automatically, making it impossible to resize.  You need to go to the advanced options and set it to run from a RAM disk instead. Here’s the steps and a few screenshots to help:

1. Type reboot or shutdown -r now on the terminal window and wait for the Grub menu
2. Select the Grml Rescue Image Option from the Grub menu
3. Select ‘advanced options’ from the Grml boot menu
4. Select ‘copy Grml to RAM’ option

4. Repartition

1. use resize2fs to shrink the existing filesystem:

   root@grml ~ # fsck.ext4 -f /dev/vda1
   root@grml ~ # resize2fs -M /dev/vda1

2. use parted to shrink the partition and create a new LVM partition:

   root@grml ~ # parted /dev/vda
   (parted) resizepart 1 3G
   (parted) mkpart primary 3001 100%
   (parted) set 2 lvm on
   (parted) quit

3. Verify your work:

   root@grml ~ # fdisk -l /dev/vda

4. Reboot to Debian:

   root@grml ~ # reboot

5. Use LVM tools to create logical volumes:

   root@debian:~# apt-get install lvm2
   root@debian:~# pvcreate /dev/vda2
   root@debian:~# vgcreate vg1 /dev/vda2
   root@debian:~# lvcreate -L 5G -n home /dev/vg1

6. Format and mount:

   root@debian:~# mkfs.ext4 -L home /dev/vg1/home
   root@debian:~# mount /dev/mapper/vg1-home /home
   root@debian:~# df -h
   Filesystem            Size  Used Avail Use% Mounted on
   /dev/vda1             2.7G  1.5G  1.1G  58% /
   udev                   10M     0   10M   0% /dev
   tmpfs                  99M  4.4M   95M   5% /run
   tmpfs                 248M     0  248M   0% /dev/shm
   tmpfs                 5.0M     0  5.0M   0% /run/lock
   tmpfs                 248M     0  248M   0% /sys/fs/cgroup
   /dev/mapper/vg1-home  4.8G   10M  4.6G   1% /home
   /dev/mapper/vg1-tmp   976M  1.3M  908M   1% /tmp

7. Add your new volumes to /etc/fstab:

   # /etc/fstab: static file system information.
   #
   # <file system> <mount point>   <type>  <options>       <dump>  <pass>
   # / was on /dev/vda1 during installation
   UUID=22f7f3aa-4357-445b-b324-9b86ee23a508 /               ext4    errors=remount-ro 0       1
   /dev/mapper/vg1-home  /home  ext4   defaults,nosuid,nodev   0    2
   /dev/mapper/vg1-tmp   /tmp   ext4   defaults,nosuid,nodev   0    2

5. Enjoy!

Go forth and partition your system logically according to your every whim!