Avoid error: /boot filled up, cant upgrade

[dino99]

Reporting against 'apt' but 'dpkg' is also concerned

Explanation:
since a while numerous users are posting threads on ubuntuforums asking help about that issue, like that one:
http://ubuntuforums.org/showthread.php?t=2282707

Proposition 1:
either 'apt' and/or 'dpkg' conf files need a feature to set the max number of installed kernels. That setting entry should be modifiable via dconf-editor, and set by default to '2'

Upgrade process:
apt/dpkg automatically purge the oldest non wanted headers/images after a new kernel installation (installing & purging in the same process)

That way the non techies users ignoring the mandatory manual maintenance will be safe with /boot.

Proposition 2:
set a monthly cronjob to run 'apt-get clean' 'apt-get autoclean' 'apt-get autoremove' to clean up the system.
But the sad effect is that the cache is purged, not only the unwanted old installed kernels

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: apt 1.0.9.10ubuntu1
ProcVersionSignature: Ubuntu 4.0.0-1.2-generic 4.0.5
Uname: Linux 4.0.0-1-generic i686
NonfreeKernelModules: nls_utf8 btrfs xor raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c cpuid binfmt_misc cfg80211 pci_stub vboxpci vboxnetadp vboxnetflt vboxdrv nvidia snd_hda_codec_hdmi snd_hda_codec_realtek coretemp snd_hda_codec_generic kvm_intel snd_hda_intel kvm snd_seq_midi snd_hda_controller drm snd_seq_midi_event snd_hda_codec snd_rawmidi snd_seq snd_hwdep serio_raw snd_pcm snd_seq_device snd_timer 8250_fintek lpc_ich asus_atk0110 snd i82975x_edac soundcore shpchp edac_core mac_hid ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 ipt_REJECT nf_reject_ipv4 nf_log_ipv4 nf_log_common xt_LOG xt_multiport xt_limit xt_tcpudp xt_addrtype nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack ip6table_filter ip6_tables nf_conntrack_netbios_ns nf_conntrack_broadcast nf_nat_ftp nf_nat nf_conntrack_ftp nf_conntrack iptable_filter ip_tables x_tables parport_pc ppdev lp parport autofs4 hid_generic usbhid hid pata_acpi ahci libahci pata_jmicron sky2
ApportVersion: 2.17.3-0ubuntu4
Architecture: i386
CurrentDesktop: GNOME
Date: Tue Jun 16 14:32:06 2015
SourcePackage: apt
UpgradeStatus: No upgrade log present (probably fresh install)

[Jarno Suni (jarnos)]

An alternative is to configure unattended upgrades to automatically remove unused dependencies: https://bugs.launchpad.net/ubuntu/+source/unattended-upgrades/+bug/1294195

[Jarno Suni (jarnos)]

Note that 'apt-get autoremove' does not remove kernels that are marked as manually installed.