Comment 105 for bug 798414

For those that can no longer run autoremove (like me, above), and don't like messing around int he /boot drive without someone else giving them reassurance, here's what I did:

# figure out what the oldest kernel files are named (version) so you can delete them:

(tp)hobson@hobs-dell:/boot$ ls -al
total 224219
drwxr-xr-x 5 root root 3072 May 14 10:47 .
drwxr-xr-x 23 root root 4096 May 10 08:50 ..
-rw-r--r-- 1 root root 1312643 Feb 25 19:17 abi-4.2.0-30-generic
-rw-r--r-- 1 root root 1312645 Mar 10 16:11 abi-4.2.0-34-generic
-rw-r--r-- 1 root root 1313029 Mar 15 17:45 abi-4.2.0-35-generic
-rw-r--r-- 1 root root 1313407 Apr 18 12:49 abi-4.2.0-36-generic
-rw-r--r-- 1 root root 184888 Feb 25 19:17 config-4.2.0-30-generic
-rw-r--r-- 1 root root 184888 Mar 10 16:11 config-4.2.0-34-generic
-rw-r--r-- 1 root root 184888 Mar 15 17:45 config-4.2.0-35-generic
-rw-r--r-- 1 root root 184888 Apr 18 12:49 config-4.2.0-36-generic
-rw-r--r-- 1 root root 945 Mar 15 18:07 crontab -u root
drwx------ 3 root root 4096 Dec 31 1969 efi
drwxr-xr-x 5 root root 1024 May 10 08:51 grub
-rw-r--r-- 1 root root 9392125 Feb 12 08:29 initrd.img-4.2.0-21-generic
-rw-r--r-- 1 root root 35759751 Feb 29 09:07 initrd.img-4.2.0-30-generic
-rw-r--r-- 1 root root 35783679 Mar 15 17:57 initrd.img-4.2.0-34-generic
-rw-r--r-- 1 root root 35807230 Apr 12 08:32 initrd.img-4.2.0-35-generic
-rw-r--r-- 1 root root 35808742 May 10 08:51 initrd.img-4.2.0-36-generic
drwx------ 2 root root 12288 Nov 9 2015 lost+found
-rw-r--r-- 1 root root 182704 Aug 27 2015 memtest86+.bin
-rw-r--r-- 1 root root 184380 Aug 27 2015 memtest86+.elf
-rw-r--r-- 1 root root 184840 Aug 27 2015 memtest86+_multiboot.bin
-rw------- 1 root root 3744565 Feb 25 19:17 System.map-4.2.0-30-generic
-rw------- 1 root root 3744589 Mar 10 16:11 System.map-4.2.0-34-generic
-rw------- 1 root root 3745312 Mar 15 17:45 System.map-4.2.0-35-generic
-rw------- 1 root root 3745958 Apr 18 12:49 System.map-4.2.0-36-generic
-rw------- 1 root root 6808720 Feb 25 19:17 vmlinuz-4.2.0-30-generic
-rw------- 1 root root 6810648 Feb 29 09:07 vmlinuz-4.2.0-30-generic.efi.signed
-rw------- 1 root root 6808528 Mar 10 16:11 vmlinuz-4.2.0-34-generic
-rw------- 1 root root 6810456 Mar 14 08:58 vmlinuz-4.2.0-34-generic.efi.signed
-rw------- 1 root root 6829104 Mar 15 17:45 vmlinuz-4.2.0-35-generic
-rw------- 1 root root 6831032 Apr 5 09:02 vmlinuz-4.2.0-35-generic.efi.signed
-rw------- 1 root root 6830512 Apr 18 12:49 vmlinuz-4.2.0-36-generic
-rw------- 1 root root 6832440 May 10 08:51 vmlinuz-4.2.0-36-generic.efi.signed

# insert your oldest kernel version number here:

(tp)hobson@hobs-del:/boot$ sudo rm *4.2.0-30*

# that should give you enough breathing room for gzip and autoremove to operate:

(tp)hobson@hobs-del:/boot$ sudo apt-get autoremove -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 69 not upgraded.
5 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up linux-image-extra-4.2.0-36-generic (4.2.0-36.41) ...
run-parts: executing /etc/kernel/postinst.d/apt-auto-removal 4.2.0-36-generic /boot/vmlinuz-4.2.0-36-generic
run-parts: executing /etc/kernel/postinst.d/dkms 4.2.0-36-generic /boot/vmlinuz-4.2.0-36-generic
run-parts: executing /etc/kernel/postinst.d/initramfs-tools 4.2.0-36-generic /boot/vmlinuz-4.2.0-36-generic
update-initramfs: Generating /boot/initrd.img-4.2.0-36-generic
run-parts: executing /etc/kernel/postinst.d/pm-utils 4.2.0-36-generic /boot/vmlinuz-4.2.0-36-generic
run-parts: executing /etc/kernel/postinst.d/unattended-upgrades 4.2.0-36-generic /boot/vmlinuz-4.2.0-36-generic
run-parts: executing /etc/kernel/postinst.d/update-notifier 4.2.0-36-generic /boot/vmlinuz-4.2.0-36-generic
run-parts: executing /etc/kernel/postinst.d/zz-update-grub 4.2.0-36-generic /boot/vmlinuz-4.2.0-36-generic
Generating grub configuration file ...
Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported.
Found linux image: /boot/vmlinuz-4.2.0-36-generic
Found initrd image: /boot/initrd.img-4.2.0-36-generic
Found linux image: /boot/vmlinuz-4.2.0-35-generic
Found initrd image: /boot/initrd.img-4.2.0-35-generic
Found linux image: /boot/vmlinuz-4.2.0-34-generic
Found initrd image: /boot/initrd.img-4.2.0-34-generic
Adding boot menu entry for EFI firmware configuration
done
Setting up linux-image-generic (4.2.0.36.39) ...
Setting up linux-generic (4.2.0.36.39) ...
Setting up linux-signed-image-generic (4.2.0.36.39) ...
Setting up linux-signed-generic (4.2.0.36.39) ...