Romoving Old Proxmox Kernels

This is optional, but normally I first run # apt update && apt dist-upgrade and then reboot the server, so it’s running the latest updates/kernels. After updating and rebooting the server, verify all your VMs and Containers are running fine.

Next, I run # uname -r, to find the “current” active running kernel, and make a note of it, for example:

#root@proxmox:~# uname -r
4.15.10-1-pve

Next, I do # dpkg –list|grep pve-kernel to show the list of installed pve-kernels. In the output below, we focus only on “pve-kernel-x-x-x-pve”, We do not touch pve-firmware and pve-kernel-x.xx

root@proxmox:~# dpkg --list|grep pve-kernel

ii pve-firmware 2.0-4 all Binary firmware code for the pve-kernel [do not ever touch!]
ii pve-kernel-4.13 5.1-43 all Latest Proxmox VE Kernel Image [not valid, does not have “-pve” at end]
ii pve-kernel-4.13.16-1-pve 4.13.16-43 amd64 The Proxmox PVE Kernel Image [valid kernel to remove]
ii pve-kernel-4.15 5.1-2 all Latest Proxmox VE Kernel Image [not valid, does not have “-pve” at end]
ii pve-kernel-4.15.10-1-pve 4.15.10-2 amd64 The Proxmox PVE Kernel Image [do not remove since this is current kernel! ]

Now in the sample above, I want to remove “pve-kernel-4.13.16-1-pve”, and also the kernel entry in grub menu, so to do this I do:

# apt purge pve-kernel-4.13.16-1-pve

Note: if you only do # apt remove pve-kernel-x-x-x-pve, it will leave the old kernel grub entry in grub menu

It will now say:

root@proxmox:~# apt purge pve-kernel-4.13.16-1-pve
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
proxmox-ve* pve-kernel-4.13* pve-kernel-4.13.16-1-pve*
0 upgraded, 0 newly installed, 3 to remove and 0 not upgraded.
After this operation, 252 MB disk space will be freed.
Do you want to continue? [Y/n]

Now at this point double and triple check to make very sure that’s the kernel you want to purge and say “Y”. It will then uninstall the kernel, purge and delete the kernel entry in grub menu, and update grub menus.

Credit: GadgetPig, https://forum.proxmox.com/threads/clean-old-kernels.42040/ – Apr 26, 2016