Resize VM partition without erasing data

I want to resize a partition from a virtual machine without erasing any data.

I only have access to this VM via SSH, so I am not able to run a live CD.

The OS is Ubuntu 14.04.2 LTS.

My current partitions are:

Number Start End Size Type File system Flags
1 1049kB 256MB 255MB primary ext2 boot
2 257MB 10,7GB 10,5GB extended
5 257MB 10,7GB 10,5GB logical lvm

I have 10,7GB unallocated.df -h output:

Filesystem Size Used Avail Use% Mounted on
/dev/mapper/server--vg-root 7,6G 5,8G 1,4G 81% /
none 4,0K 0 4,0K 0% /sys/fs/cgroup
udev 2,0G 4,0K 2,0G 1% /dev
tmpfs 396M 516K 395M 1% /run
none 5,0M 0 5,0M 0% /run/lock
none 2,0G 0 2,0G 0% /run/shm
none 100M 0 100M 0% /run/user
/dev/sda1 236M 43M 181M 20% /boot

My /dev/sda has 21.5GB and I am only using about 10GB

All the tutorials that I've found requires a live CD.

Any idea how can I manage to do that?

Thanks

3 Answers

It doesn't look like you actually have the empty space available - the "extended" partition usually covers all remaining disk space. It's possible that you do ; particularly if you created the disk image at 10GB and then it was resized to 20GB.

So, presuming you do have the empty space, you need to :

• Make sure you have backups!
• Resize the extended partition to fill the new upper sector limit
  • Use fdisk for this
  • Be careful! fdisk can wreck your partition table
  • A method for doing that is here : resize/grow partition without losing data
  • The method can be summarized as
    • Remove the existing partitions (2 and 5)
    • Recreate them with exactly the same starting sector numbers
    • For partition 2, allow it to consume the whole disk
    • For partition 5, use the exact starting sector and size it has now
• Enrol a new LVM partition in the root volume group
  • Create a new Linux LVM partition in the extended space, allow it to consume remaining disk space
  • Make this a "physical volume" with pvcreate /dev/sdaX where X is the new partition
  • List the volume groups
    • vgdisplay
  • Extend the server volume group (replace name with name from previous step as required)
    • vgextend server-vg /dev/sdaX
  • Show the logical volumes
    • lvdisplay
  • Extend the root fs volume
    • lvextend /dev/server-vg/root /dev/sdaX
  • Resize the root FS to fit the new space
    • Depends on the FS you're using... e.g. for ext based FS
    • resize2fs /dev/server-vg/root

References :

I did it in a VM with Ubuntu Server 18.04 and without LVM.

Initial state after increase the HDD in VirtualBox.

ivanx@ivanx:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 40G 0 disk
├─sda1 8:1 0 1M 0 part
└─sda2 8:2 0 20G 0 part /

Next step is to delete the partition and resize with fdisk.

ivanx@ivanx:~$ sudo fdisk /dev/sda
Welcome to fdisk (util-linux 2.31.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): p
Device Start End Sectors Size Type
/dev/sda1 2048 4095 2048 1M BIOS boot
/dev/sda2 4096 41940991 41936896 20G Linux filesystem
Command (m for help): d
Partition number (1,2, default 2): 2
Partition 2 has been deleted.
Command (m for help): p
Device Start End Sectors Size Type
/dev/sda1 2048 4095 2048 1M BIOS boot
Command (m for help): n
Partition number (2-128, default 2): 2
First sector (4096-83886046, default 4096): 4096
Last sector, +sectors or +size{K,M,G,T,P} (4096-83886046, default **83886046**):
Created a new partition 2 of type 'Linux filesystem' and of size 40 GiB.
Partition #2 contains a ext4 signature.
Do you want to remove the signature? [Y]es/[N]o: N
Command (m for help): p
Device Start End Sectors Size Type
/dev/sda1 2048 4095 2048 1M BIOS boot
/dev/sda2 4096 83886046 83881951 40G Linux filesystem
Command (m for help): w
The partition table has been altered.
Syncing disks.

Check results:

ivanx@ivanx:~$ df -h
/dev/sda2 20G 19G 466M 98% /
ivanx@ivanx:~$ sudo resize2fs /dev/sda2
resize2fs 1.44.1 (24-Mar-2018)
Filesystem at /dev/sda2 is mounted on /; on-line resizing required
old_desc_blocks = 3, new_desc_blocks = 5
The filesystem on /dev/sda2 is now 10485243 (4k) blocks long.
ivanx@ivanx:~$ df -h
/dev/sda2 40G 19G 20G 49% /

Why not try GParted? It has a GUI and allows [partition resizing and data moving.