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Attack by ZmEu

Who is ZmEu?

An image showing ZmeuThe name Zmeu (no capital E) is the name of a fantastic creature of Romania. There are so many stories that there isn't a clear understanding of what it is... but it is human like, can spit fire and wants to marry young women.

If you're wondering, it is generally a bad guy.

ZmEu Attack

Today, I noticed a lot of traffic on one of my servers. Looking into what was happening, I immediately found out that an attacker was looking for a loophole in that system. That attack was being performed from China.

Repair a Cassandra Cluster

I use the Cassandra database cluster system to manage a new set of websites and once in a while I start getting many errors and the website stops working altogether.

When that happens, it is likely that Cassandra broke something in the temporary tables that it holds. The only way to go past that problem is to clear those tables. Until then, it will fail over and over again (they really would need some euristic to auto-clean up even if it means that you're losing some data.)

The command to repair the database, really quick, is as follow:

nodetool scrub snap_websites files

Note that ...

nvidia_XXX.ko No Such Device

Today I got a new video card because it looks like the old one I had was going bad. I hope that was not my KVM, although we'll see when it gets hot again, whether the video goes bouncy again or not... If not, then the old card is good for the trash (although it works in console mode just fine!)

So I got a new card. My old one was a NVidia GT 220. Fairly old model. Yes.

The new card is an NVidia GT 630 (to be precise: Asus GT630-SL-2GD3-L.)

When I tried to start X11, I saw an error (really quick) and the system did not come up. Looking closer into the matter, I could see that the NVidia ...

Why are my "vim: ..." commands not activated?

I use gVim all the time, I like that editor very much (emacs is just way too much, if you ask me.)

But once in a while I install a new server and by default they generally turn off the modeline feature. This is because there are potential security risks in link with that feature (i.e. vim starts running whatever script is defined in the text files that you edit...)

Anyway, I most often forget about the command to enable my:

vim: <setup>

(I most often define the tab stops, corresponding shift width and eventually the syntax of a file.)

Only, on those new servers, that doesn't ...

HP Printer options not offering "Color: Off" option anymore

As I upgraded to Ubuntu 13.10, I noticed that I lost the option to turn off the color when printing.

Looking around all the available options, no one to make it black and white (although the old option was saying something like: Color: Off; it was somewhat weird.)

Now that option is completely gone. There is no way for me to turn off my HP Printer color when I am in Acrobate or LibreOffice. I searched on the Internet to see whether that was just HP trying to get you to use colors on your printer or whether the option was available... somewhere else.

Indeed, I had to go to the System ...

Setting tag attributes in a dynamic way in XSLT with XQuery

I wanted to dynamically manage the attributes of the HTML tag. As I'm working on the Snap! C++ system, I thought that should be done with the standard XSLT feature: <xsl:attribute-set name="...">. Unfortunately the the XQuery implementation does not currently support such, at all.

There is a way, though, to still make it work with a central template definition which can be used to decide what should be and what should not be added to the HTML tag.  Especially, in this way we can make use of one template that is a system defined template. This being said, if you use ...

Large scale Linux console

As I am working on our Snap! C++ CMS, I created a set of virtual systems to test the compilation on "clean" system (yeah! my main computers has all sorts of things that I don't even know about...)

In those virtual system, I only install the basic server and then do a sudo apt-get install of anything else the server needs to get compiled. This includes libraries such as libmagic, boost, and Qt and some tools like xmllint. This is pretty cool, but when working in a console, and that console is very small, it makes it a bit difficult, so I looked into making it big.

For this ...

Remote access to another MS-Windows computer

I have used several different software to gain remote access to other's computers.

With a Unix system, it's easy. You use ssh and you can do everything you want (although some people just cannot handle a console, I'm fine with such, but ssh allows you to access X-Windows if you'd like with the -X command line option.)

With MS-Windows, since that system is just a desktop application, you need a special tool in order to achieve that feat. Most of them are for money or make use of things that do not work under Linux. Yet, there is one that I like, it is called TeamViewer. It was ...

tripwire --init not saving the database

I ran in a problem with tripwire, it did not want to generate the <hostname>.twd file under /var/lib/tripwire

I could see that because it reports, once a day, whether tripwire ran sucessfully or not. It was not and the main error was: the tripwire database does exist which is actually shown as:

### Error: File could not be opened.
### Filename: /var/lib/tripwire/<hostname>.twd
### No such file or directory
### Exiting...

That, in itself, looks easy to fix. So I ran tripwire --init and voià!

sudo tripwire --init

As usual, it print a few errors and ignored them.

Postfix says it does not allow relaying?!

As we are upgrading our server to jump from version 12.04 to 13.04, we encounter a few problems.

Two with Postfix, first the Postgrey port has changed. It was 60000 before, now it is 10023. Don't ask me... Anyway, that was the easy one.

The other problem was a relay error. I could send emails all I wanted, but not my partner who does not show his server as part of our Made to Order Software Corp. network. Relay is why a computer allows emails from server X to be sent to server Y through server Z. You are server Z, that's the relay.

The fact is that if you can log in your account on ...

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