How do I resize my /boot partition?

/boot has become 100% full somehow.

df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/ubuntu-root 191078052 31758960 149612804 18% /
udev 3997520 8 3997512 1% /dev
tmpfs 1602244 856 1601388 1% /run
none 5120 0 5120 0% /run/lock
none 4005600 1792 4003808 1% /run/shm
none 102400 28 102372 1% /run/user
/dev/sda1 233191 218740 2010 100% /boot
mount
/dev/mapper/ubuntu-root on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755)
/dev/sda1 on /boot type ext2 (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
vmware-vmblock on /run/vmblock-fuse type fuse.vmware-vmblock (rw,nosuid,nodev,default_permissions,allow_other)
gvfsd-fuse on /run/user/foo/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,user=foo)

How can I make the space allocated to /boot bigger?

There is a related question How do I free up more space in /boot? but that is not what I want to do.

Added.

Disk /dev/sda: 200.0 GB, 200049647616 bytes
255 heads, 63 sectors/track, 24321 cylinders, total 390721968 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
Disk identifier: 0x0007f9dc Device Boot Start End Blocks Id System
/dev/sda1 * 2048 499711 248832 83 Linux
/dev/sda2 501758 390721535 195109889 5 Extended
/dev/sda5 501760 390721535 195109888 8e Linux LVM
Disk /dev/mapper/ubuntu-root: 198.8 GB, 198784843776 bytes
255 heads, 63 sectors/track, 24167 cylinders, total 388251648 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
Disk identifier: 0x00000000
Disk /dev/mapper/ubuntu-root doesn't contain a valid partition table
Disk /dev/mapper/ubuntu-swap_1: 1006 MB, 1006632960 bytes
255 heads, 63 sectors/track, 122 cylinders, total 1966080 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
Disk identifier: 0x00000000
Disk /dev/mapper/ubuntu-swap_1 doesn't contain a valid partition table

2 Answers

There are 2 parts to this:

1. Open a terminal and run ls /boot

   If boot is full of old kernels you can go remove happy on them, I recommend keeping the original, the latest and the one before latest. The lowest number is normally the shipping kernel, the highest number will be the latest.

2. To grow boot you first need to shrink another partition so you have free space. I would suggest using the GParted partition editor on a live Ubuntu USB to do this. First decrease the size of / or /home depending on your setup. Then increase the size of /boot.

I assume this Linux machine is a VM.

Expand the SCSI device by 1GB on VM sphere centre or AWS, etc, so /dev/sda gets an additional 1GB of space.

Reboot the server to single user mode. Use fdisk -l /dev/sda to confirm the new size with additional 1GB.

Use fdisk /dev/sda to create an sda3 partition with 1GB. Save the partition table. Ubuntu will require partprobe to update the partition table. Now run:

mkfs.ext4 /dev/sda3
umount /boot
dd if=/dev/sda1 of=/dev/sda3
e2fsck -y /dev/sda3
resize2fs /dev/sda3
e2fsck -y /dev/sda3

Now update /etc/fstab (be sure to make a backup copy, just in case need to boot from CDROM/DVD to recover), update the line to mount /dev/sda3 on /boot (and comment the line for /dev/sda1)

Mount /boot

df -k should see /boot is 1GB now, but you need to make it the default boot device.

Use fdisk /dev/sda, and press p to print the partition table. You will see /dev/sda1 is the default boot device.

Use the a command in fdisk to disable /dev/sda1 as default boot device and again to enable /dev/sda3 as default boot device. p to show partition table.

 Device Boot Start End Blocks Id System
/dev/sda1 2048 411647 204800 83 Linux
/dev/sda2 411648 20971519 10279936 5 Extended
/dev/sda3 * 20971520 23068671 1048576 83 Linux
/dev/sda5 413696 20971519 10278912 8e Linux LVM

Reboot

After you've been online for sometime, if you feel you want to utilize the 200MB of /dev/sda1, just recreate /dev/sda1 and put into any VG you want.