Mostly Harmless

I’ve been looking for something like this for a while now to make my quick solutions posts more readable. Only tested it on one post so far but seems to work on latest WP and Thematic.  The little plugin allows you to display  Linux terminal input / output in a “pretty” fashion in your posts, you can also customise the user@computer if you wish. Thanks

Odd error when running yum update on my slice. This appears to be a currently outstanding bug which can be worked around by issuing a

or

The former worked fine for me. Original error shown below.

It’s possible that this is the error reported fixed here in RHEL. The version on CentOS doesn’t seem to have caught up yet.

Encountered a rather odd error, two HP Vista laptops failing to copy large files to network shares, these would error out complaining about being able to access the source file on the local disk, which was a rather confusing way of reporting the error as there was no problem with the local disk.  On network transfers of lots of files of varying sizes over wireless, they’d drop the wireless connection entirely.  The only way around this was to use a cable when copying files over the network.

Following a little research this appears to be a reasonably widely experienced issue with a particular Windows configuration option in some environments. You can change this using an administrative command prompt by entering the following command

netsh interface tcp set global autotuninglevel=disabled

(To open an administrative command prompt, right click on a command prompt entry on your desktop or start menu and choose “Run as Administrator”. If you use a standard command prompt to issue the command you’ll get a permissions error).

More information on these settings can be found here. What I haven’t yet come across is a KB article explaining the issue in more detail (i.e with a list of routers this may be a problem with), which seems rather unfortuntate.

One of the things about having your own little server, not really used for anything absolutely critical to anyone is that you can install updates as soon as you like. Non critical updates are one of those things that you have to do sooner or later and for non critical systems it can often be appropriate to install them as and when they arrive, rather than spending a larger amount of time performing monolithic updates once a year or more. They also tend to challenge the techie in you from time to time… like this little lot on my x86_64 CentOS Slice.

Downloading Packages:
Running rpm_check_debug
ERROR with rpm_check_debug vs depsolve:
Package mkinitrd needs nash = 5.1.19.6-28, this is not available.

Oh dear. Messages like this are occasionally just a mistake somewhere in the chain, leave the updates a few days if you were only doing it because you were bored anyway and the error might just have solved itself by the time you come back…

…Not in this case however. So on we go.

The error message produced by Yum in this case is a bit useless as it omits information about the architecture of the package, let’s see exactly what’s installed with “rpm -q“.

# rpm -q mkinitrd
mkinitrd-5.1.19.6-28
mkinitrd-5.1.19.6-28

Two packages.  I vaguely remember a discussion from the Slicehost forums on possibly unnecessary packages installed by default. So, let’s see if these packages are from different architectures.

# rpm -q –qf ‘%{name}-%{version}-%{release}.%{arch}\n’ mkinitrd
mkinitrd-5.1.19.6-28.x86_64
mkinitrd-5.1.19.6-28.i386

So they are. If we’re feeling brave and we’re reasonably sure we don’t actually need the i386 package,we can remove it.

rpm -e mkinitrd.i386

Which get’s us past that error. But then another pops up with a variety of packages, all of the below variety.

file /usr/share/man/man8/avcstat.8.gz from install of libselinux-utils-1.33.4-5.1.el5 conflicts with file from package libselinux-1.33.4-5.el5

So, exactly what other packages are on here that aren’t x86_64?

yum list *.i386

At this point, if we’re sure we don’t want the i386 packages the above command returns (i.e you’re sure you aren’t making use of multilib and don’t require the packages on your system) we can remove them using Yum, as this will tell us whether any software we’ve installed via the package manager actually depends on them. Anything you’ve compiled yourself however won’t be reported.

yum erase *.i386

This also showed up an i686 package, which we can double check for others of the same type and remove in a similar manner to above.

The CentOS upgrade then proceeded as expected

• Note: Before removing packages, be sure to keep a log of exactly what you’re doing and everything that was output to terminal for each command run if you aren’t sure what you’re doing. This will be invaluable if you have to call for help.

• If there are packages knocking around on your system and you aren’t sure why, a good place to start is /var/log/yum.log – it may well jog your memory on anything you’ve installed and forgotten about

• If you’re upgrading a remote system make sure you have a way to access it if it won’t boot, on Slicehost of course you have this with the recovery console available in Slicemanager, otherwise you may want to ask your provider to hook you up a KVM for that nailbiting first reboot after the upgrade.

This is obvious, but also clever in the way of many clever things in that the attack is only obvious after it’s been explained to you. In short, if an attacker sucessfully impersonates someone you know, or gives you the impression you may / should know them, they may be able to exploit you.

Like many things, social networking sites are great until you let people use them. Yes there’s a certain disappointment when you discover a contact now hides their friends list, you can wonder what you’ve done wrong (although admittedly not so much as when that “view photos of so and so” link you used to use to browse pictures of said contact in their bikini that person to see how they were doing suddenly disappears from view. Does anyone know if the default setting on facebook is now to hide the friends list? (I doubt it somehow).

It occurs to me more and more that maybe we need to get away from being so tribal (trusting people because they look like us, or our friends appear to know them and immediately distrusting people who seem odd) and through getting most of our information once it has been squeezed into convenient stories or concepts, even if those don’t evoke much of a response anymore (see below). Funnily enough you can just imagine anyone reading this post through after it gets linked on facebook, tutting or uttering “oh dear”.  Ho Hum.

Fairly often, people ask how they can keep their children safe on the Internet, or how they can lock out certain areas through address blocking or access control software. I generally liken the Internet to a city, if you’re buying your child a fully Internet capable device that they can use without your supervision, you’re letting them roam free in a city, with all the attendant opportunities and dangers that come with that.

Despite the fact the analogy is obvious,  it’s heartening to know if they like QI I can just email them this link in future, in order to be backed up by the eloquence of Stephen Fry.  Relevant quote reproduced below for convenience.

This is an early thing I said about the internet at the time things like AOL were still huge. I said it’s Milton Keynes, that’s the problem with it. It’s got all these nice, safe cycle paths and child-friendly parks and all the rest of it.

But the internet is a city and, like any great city, it has monumental libraries and theatres and museums and places in which you can learn and pick up information and there are facilities for you that are astounding – specialised museums, not just general ones.

As important as the more traditional cultural institutions?

But there are also slums and there are red light districts and there are really sleazy areas where you wouldn’t want your children wandering alone.And you say, “But how do I know which shops are selling good gear in the city and how do I know which are bad? How do I know which streets are safe and how do I know which aren’t?” Well you find out.

What you don’t need is a huge authority or a series of identity cards and police escorts to take you round the city because you can’t be trusted to do it yourself or for your children to do it.

And I think people must understand that about the internet – it is a new city, it’s a virtual city and there will be parts of it of course that they dislike, but you don’t pull down London because it’s got a red light district.

The search terms people use to come across your website are a constant source of amusement. This has to be one of the best ever *drumroll*

“free harmless bs media player”

Microsoft, I hope you’re listening for Windows Media Player 12… I wonder if this particular visitor found what he was looking for, or if when he searches for the term next month he comes across this

These days, gallery is a massive image oriented CMS (so much so that the developers are refocusing on their core objectives for Version 3), with a ton of modules / plugins and themes. It should be no surprise therefore that it’s easy to add a cart / checkout to it.

Continue reading Configuring a Paypal Checkout on Gallery 2

(Or how to Install GTA IV PC if you’re getting CRC errors).

We’ve come a long way since you used to have to have a PC to play the best games. Granted a £2000 PC with a £400 screen will still out perform any console out there but these days you get to play most of the big releases on the consoles as well and increasingly you’ll get to play them there first.

The “burden of screwing around” however on PC is now beyond a joke. It took the best part of an entire afternoon to install GTAIV PC from the two DVDs it comes on because of repeated CRC errors stopping the install progressing. After trying everything to correct these I dropped to Windows safe mode and the thing installed without any errors. I can thus only assume that the copy protection that comes with the game was interfering with something already installed on my machine. A quick search reveals that I’m not the only one and other people out there are getting replacement DVDs and in some cases hard disks (both of which can legitimately cause CRC errors if they’re failing). Uninstalling your CD burning programs (Nero, DirectCD etc) should NOT be a requirement simply to bypass an issue with over zealous copy protection.

It’s been said in forums a million times over but you’re now better off illegally downloading your PC games, with the copy protection hacked out than you are going to a shop and making a legitimate purchase.  For years now I’ve tried to convince people that you’re better off buying the games you like, so that more like it are made in future, but I really don’t believe my own words anymore.

If the PC does dramatically decrease in market share games wise, this will be a pity, because the PC will nearly always be the most technologically advanced platform for developers to play on and they deserve the budgets to match.

From a consumer perspective however, that PS3 is looking vastly tempting…

Like many this Christmas, I found Amazon’s offer of £3 of free MP3s tempting. I’ve avoided buying music online all these years on principle because the DRM experience mixed with using multiple computers and OS types has just been miserable. The CD has generally been cheaper, with the very minor inconvenience of ripping it when it first arrives to a nice high bitrate play-anywhere set of files.

So, like a mug off I merrily go to order my MP3s of choice, supposedly free of DRM or any other BS. However, once you get through the ordering process, you’ll find that some BS has persisted. If you have ordered more than one track you are not served a direct download of each track, or a zip of everything you have ordered. You are prompted to download an app with the promise that it’ll add the tracks to your iTunes or Windows Media Player collection. Grand and all that, if you actually use either of these apps, which on windows I don’t. Alarm bells ring.

Still, there are download links for a variety of Linux flavours, so I give it a whirl. The download for OpenSuse 11 doesn’t work immediately on 11.1 due to missing dependancies, no biggy there we’ll just make sure the correct libs are installed for that architecture via the package manager.  After some messing around and a little searching it turns out the app has never installed properly

To be fair, fire up Windows in a VM and the little app installs without issue, however by default it still tries to insert every track into Windows Media Player, which if you’ve not clicked through the setup wizard for media player will result in a prompt for every single track.

On one hand the app is quite neat, you get served a little file which presumeably has information about which tracks to fetch encrypted within it and off it goes and grabs them. Unfortunately it’s just unnecessary, an online store should not need a helper app to serve unprotected DRM free MP3 files and if you are going to make a helper app compulsory, at least make sure it works. Oh, and if you’re going to serve a little encrypted file people might not know what to do with instead of a music download, make sure it can be redownloaded easily from the order history (I couldn’t find an option to re-download at all, but had saved the original file).

Back to ordering CD’s and ripping them it is.

Still, “And all that could have been” was worth the trouble. (Note, fan made video below includes stuff you might not want to see etc etc…)