My Server was just down for an Upgrade.

From 14h30 until 15h30, I needed to do some upgrading to the hardware of the computer which I name ‘Phoenix’.

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This old computer from 2008 may be running the most powerful Linux version at my disposal, in 64-bit mode, and its dual-core CPU may clock up to 2.6GHz, but until now, it had still only possessed 2GB of RAM! This box still uses DDR2 RAM modules, and I had upgraded it from 2x 512MB to 2x 1GB in the year 2008. But what I needed to do today, was to upgrade it to 2x 2GB, finally giving it its maximum of 4GB of RAM.

This time around, I no longer felt I’d have the dexterity to prevent static damage to the RAM modules, just by controlling the sequence with which I touched parts. And so this time, I also felt I needed to use an actual anti-static bracelet.

Further, the CPU heat sink was plugged full of dust, so that the CPU fan was no longer able to push any cooling air through it. I knew for a long time that this also needed to be remedied, but had procrastinated in doing so. While I had the tower open today, I also took care of the dust in the CPU heat sink, with a bottle of compressed gas.

One reason I was not so eager to do this much-needed work, was the knowledge that if I had botched this, I’d have lost my one and only server. But I was also reminded, that if the server was to fail, because the CPU was consistently running too hot, the outage would take longer than 1 hour to fix. And so I finally chose the 1 hour preventative action.

I am glad that now the CPU is being cooled properly again, and that I finally have 4GB of RAM on this 64-bit machine.

Also, this was one situation in which I could not post a Maintenance Mode Notice on my blog, because for 1 hour, there was no server to render the Maintenance message screen.

Dirk

 

I’ve Upgraded my Permalinks.

There was a subject in Web-hosting, which I was not even aware of until recently. Often, when a site offers URLs to the browser, those URLs contain a question-mark, followed by variables and values, such as Posting Numbers. Those question-marks explicitly invoke a CGI script on the server, which in this case is written in PHP.

Well as long as that’s happening, the URLs are not fully ‘permalinks’. Full permalinks are URLs which seem to extend beyond the real file system with slashes, and which the Web site rewrites in-place, when the browser requests them, to translate them into CGI-calls. This requires a server module to be loaded, which in the case of Apache is named ‘mod_rewrite.c’ , and of course it requires that the rules for doing so be defined, before the CGI script is even invoked.

Until very recently it was not really necessary for the links on my blog to be of that type. But what I’ve just done in the past few days, was make the site multilingual. And since this relies on machine translations, this can look very ugly to search engines. So with my new rewrite rules, the German translation of my site is virtually at

dirkmittler.homeip.net/blog/de

And the French version is at

dirkmittler.homeip.net/blog/fr

That way the search engines can keep them all nice and tidy, even though those are the derived ones.

And naturally, from about 14h30 through 15h00 today, clicking on the actual, new permalinks also caused some 404 Errors, until I got all that sorted out, which it should be by now. If people are having later problems with the new permalinks, please leave me a Comment about it…

Dirk

 

There has been a Dist-Upgrade on my Server.

This server is hosted on a Debian / Jessie (Linux) computer which I own and run myself. Under Debian – Linux systems, the most thorough kind of update which can be carried out is called a ‘dist-upgrade’ or a ‘d-u’ for short. Just this evening, I saw that suddenly there were 93 software packages, which all did need an upgrade, and saw, that I could not just leave this type of upgrade to the usual, automated services. Therefore, I decided to administer the 93 package-upgrades given, via a dist-upgrade command. This can be stressful, or exciting, or both, because it can give a Linux user an improvement, or it can in some cases actually cripple our systems. I’m glad to say that this Linux box I name ‘Phoenix’ did not get crippled. It’s still fully bootable.

But due to this procedure, the Web-server was also down, from 20h15 through until 20h40 or so. I see that my blog is still here though, after the d-u .

I think that most software updates can be fun and games. But this particular upgrade also chose to include my graphics driver, which I was particularly fussy about. The past version of the graphics driver on this box was extremely stable, and I was trying to avoid doing any sort of upgrade to it, but now doing so was the only way to keep my box compatible with future upgrades.

It has sometimes happened to me, that the screen might just freeze – even though it’s a Linux computer – due to stability problems with other graphics drivers – especially with the ‘mesa’ driver, which tries to software-render an OpenGL equivalent. But what has been most stable for me in recent months, was the ‘GLX’ driver, which does full hardware, OpenGL rendering as it’s supposed to, and which under modern Linux systems is even capable of a ‘TDR’ equivalent, a Timeout Detection and Recovery, which will restart a crashed GPU without harming the active session.

If in the near future I find that my screen does freeze, or that there are TDR issues, a sinking feeling will go through my heart, because that would signal that a completely stable graphics driver has been replaced unnecessarily, with an unstable one. And in the act of doing so, all my package-management scripts even recompiled the DKMS kernel module for the graphics driver in question, because that is the correct way to install it.

Oh Yes, I see that the Apache Web-server software, which my machine hosts, has been given an upgrade as well. But as I see it, this was the least likely set of packages, for the maintainers to have botched. So it’s my full assumption that Web-server activity will continue without error.

Dirk