On 25-07-17, Cindy-Sue Causey wrote: > On 7/25/17, Dejan Jocic <jode...@gmail.com> wrote: > > On 25-07-17, Greg Wooledge wrote: > >> On Tue, Jul 25, 2017 at 09:41:24AM +0200, Dejan Jocic wrote: > >> > When you upgrade to Jessie, it will install new kernel automatically. > >> > However, it should not remove your Wheezy kernel, because upgrading > >> > kernels always leaves one old one there, in case that you can not boot > >> > into your new kernel for some reason. You can then mark that kernel via > >> > grub options as one you would like to boot in. You can do it during > >> > boot > >> > in grub, or by setting it as default in /etc/default/grub. > >> > >> All true. > >> > >> > You will also > >> > have to use apt-mark to put that kernel on hold, to prevent removing it > >> > on future updates, or to do some apt pinning. > >> > >> False. The kernel will simply sit there forever, unless you take some > >> explicit action to remove it. No holds or pinning or other wrestling > >> required. > >> > > > > That is not true, if you use autoremove. Only 2 last kernels will be > > kept. This is upgrade from Jessie here. I have 4.9.0.2 and 4.9.0.3 > > kernels. Jessie kernel is long gone with autoremove. > > > Well, that's a little... scary. *frown* > > Except that... I just deleted the rest of what I first wrote because > it hit me. Autoremove is what apt-get tells me to use to remove > packages..... that are no longer needed.... that are no longer > "dependencies". What it actually tells *me* is something like "apt > autoremove" (not "apt-get autoremove"). > > Aaaahhhh... So in autoremove's mind... It might touch on that previous > kernel and say... hm, nothing's using it now, nothing needs it to > function properly, so trash it........ > > Or something like that.... there...... :) > > Cindy :) > -- > Cindy-Sue Causey > Talking Rock, Pickens County, Georgia, USA > > * runs with duct tape * >
What it touch is /etc/kernel/postinst.d/apt-auto-removal that generates /etc/apt/apt.conf.d/01autoremove-kernels file. Those decide what kernels to keep. And, in case of /etc/kernel/postinst.d/apt-auto-removal it is clearly stated: # Mark as not-for-autoremoval those kernel packages that are: - the # currently booted version - the kernel version we've been called for - # the latest kernel version (as determined by debian version number) - # the second-latest kernel version # # In the common case this results in two kernels saved (booted into the # second-latest kernel, we install the latest kernel in an upgrade), but # can save up to four. Kernel refers here to a distinct release, which # can potentially be installed in multiple flavours counting as one # kernel.
