On Mon 29 Jan 2018 at 13:43:20 (+0000), Joe wrote: > On Mon, 29 Jan 2018 08:18:35 -0500 > rhkra...@gmail.com wrote: > > > > > > I regularly download "security" upgrades for Wheezy. I assume that > > most of those don't take effect until I restart the application. For > > instance, a Firefox upgrade does not take effect until I shutdown > > Firefox and restart it. > > > > Correspondingly, I assume that a Linux kernel upgrade does not take > > effect until I reboot the machine. > > Yes, but it's a little more complicated. The modules used by the kernel > (and the kernel file itself) *are* replaced during the process of > upgrading the kernel, but the running code is not. There is a tiny > chance of some kind of mismatch if new modules are loaded, so rebooting > is recommended soon, and in the past I used to see a message to that > effect, displayed during the upgrade.
For the benefit of the OP, who is unaware of the meaning of version numbers, it's worth pointing out that during their upgrade, they got a new set of modules along with the kernel because the new kernel was in a new package with a new name. However, it's not clear that, having searched for a new kernel and found ("only") a 4.9.0-5 one, they have installed it. If they haven't, they need to, or else they will not receive further upgrades. Better still, install the most generic/least specific kernel metapackage so that upgrades will be automatic (or more obvious, depending on the tools used). Cheers, David.