Routine Log Rotation Suspended my IPv6 Today.

Today is May 1.

On most Linux systems, there are “log rotations” which can take place daily, weekly, or monthly. Log rotations frequently but not always require that a service be restarted. This is because while log files have been renamed, the service which is writing log data to them, retains a handle to the same file as before, unless that service is restarted. Once the service is restarted, it obtains a new handle from the O/S, for a fresh log file.

Most of my log rotations have no side-effects. But when I set up my ‘OpenVPN’ -protocol VPN server, I decided to set up a monthly log rotation associated with it, which also has as post-log-rotate job, to restart this VPN.

Oddly enough, this does not impede the VPN service from restarting. But as a side-effect, this knocks my (Debian) ‘Miredo’ client off-line every time, which gives me IPv6 connectivity when it is running, by way of a Teredo server.

It seems that the authors of ‘Miredo’ have already observed, that restarting something that upsets the IP stack in this way, can knock their client off-line, and so the makers of this package omitted any logging, or log rotation, for ‘Miredo’. But whenever by VPN server is restarted, this affects the Teredo client I just named.

Today is May 1. So therefore in a routine way, my IPv6 address was knocked off-line by the monthly log rotation this morning. And this effect lasted, until I manually restarted the Teredo client in question.

So as I am writing this, I have an IPv6 address again.



I have just had to get my hands dirty, with apt-listbugs.

According to This Posting, I have installed ‘unattended-upgrades‘ on the computer I name ‘Phoenix’, and I have also installed ‘apt-listbugs‘, as an insurance policy against ‘unattended-upgrades‘ auto-installing defective packages.

This has always posed the question of what will happen in practice, if ‘apt-listbugs‘ “pins” certain packages, thus having stopped them, but if the update-procedure needs to be reactivated later, manually. I have never had to act in this matter yet, while instead, there was one recorded occasion, on which upgrades did not take place on one day, but took place again a day later, automatically.

But just today I needed to override what ‘apt-listbugs‘ had done, manually. In particular, the question exists, of how one can get apt-listbugs to unpin an upgrade which was once scheduled, so that we can do the upgrade later, and so that we can see what apt-listbugs had to say about it.

By default, if we then simply type in ‘apt-get upgrade‘, nothing happens.

As it turns out, there is a single file named ‘/etc/apt/preferences.d/apt-listbugs‘, which we need to delete, before we can restart an upgrade process.

After I did this, my ‘apt-get upgrade‘ took place normally again, and I got to see what the error was, over which ‘apt-listbugs‘ had stopped the unattended upgrade today.



Iceweasel to Firefox Transition

In the past, there had been a split between Debian / Linux Devs, and the Mozilla team, where at first Linux was allowed to share “Firefox”. According to that split, Debian / Linux continued to develop its own version of the Web-browser, naming that “Iceweasel“. Newly, this split seems to have been resolved, so that Debian is now offering Firefox again. The packages have been made available.

Just now, I did my own transition, from the deprecated Iceweasel to Firefox. This process was quick and painless.



One Reason I now Feel that the Linux Update Process is Stable

Back in past years, the habit I had had with my Linux computers was such, that I would not do a complete upgrade of all installed packages. Instead, I would often tell my package manager to install some new packages, and view the message it generated, according to which many packages were to be held back and not updated, as part of the new installation. I used to acknowledge this in general, and allow it to happen.

By contrast, I did notice how often Windows Update does its job, and how my Windows computers were never or seldom broken by a Windows Update. However, it had happened to me on occasion, that the Linux computers could get into some sort of stability issue, over upgrades I had done. And so I had reached the vague conclusion, that Windows Update was somehow better, than the habit of doing complete upgrades under Linux.

What I now have is two computers, on which all the packages I have installed are at their most recent version, due to the ‘unattended-upgrades‘ package which I have installed, and which I wrote before in This Earlier Posting.

What I now find, is that my Linux computers that are up-to-date, are at least as stable as my Windows 7 and Windows 8.1 machines, if not more stable. And so advice which I was once given but had ignored, seems to have been accurate, according to which my earlier practice of only upgrading a minimum of libraries, was a bad practice, and according to which doing so, introduced stability problems of its own.

Having said that, If we are given a Debian / Linux machine which requires upgrades to a large number of packages, let us say to more than 20 packages, then we effectively need to do a ‘dist-upgrade‘ to achieve that most reliably, and even then, this one-time action can fail, and can leave us with an unstable or broken system.