Welcome to The Linux Page

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This site is a collection of my own work with Linux. Certain things are easy, others take time to decipher and if I ever need to repeat the work (which usually happens!), then I need to remember everything by memory or... have a site with all the steps taken and to take again.

The following are my most recent posts:

Linux Firewall "missing" igmp protocol... Watch out on reboot!

I just updated Linux to the newest version for Ubuntu 10.04 and got an error with the firewall...

 * Setting up the firewall iptables...
iptables-restore v1.4.4: Couldn't load match `igmp':/lib/xtables/libipt_igmp.so: ... 
                             ... cannot open shared object file: No such file or directory

The fact is that the iptables code is now using a set of .so files to handle each protocol and it is found in the /lib/xtables folder. And there is no libipt_igmp.so file in there... so you cannot change anything against such packets. That's it...

I tried to use 2 as the

I have different scripts that synchronize different hard drives for either backup or just synch-ing my development system with one of the production systems.

I got an error for a little while after I created a folder on a destination as I wanted to make sure that the source folder was being copied...

That generated an error as follow:

  rsync: delete_file: rmdir "<destination>" failed: Directory not empty (39)
  rsync error: some files could not be transferred (code 23) at main.c(977) [sender=2.6.9]

The fact is that the source file was a softlink and not a folder. So ...

Attack by Bots

Since the ZmEu attack, I've been watching my logs a little closer. I also found a page that I could not read (but Google could and was kind enough to provide a cached version.) That page listed many bots that are not nice bots. So? I decided to block some of them, especially those that use very bad URLs or load many pages too quickly.

The result is that I'm getting more and IP addresses in my firewall. Although they get removed in a schedule that I will not state here, I can tell you that each time I block tenth when not hundredth of useless hits (worst than that at times those could be

Deleting a database in Synergration

Synergration AccessBooksRT is a tool we use to get a copy of QuickBooks tables in an MS-Access database.

It works great for our purpose and transformed some super sluggish forms into lightning fast forms. We still use QODBC for some of the work (updates) but 99% now goes through the database generated by Synergration instead.

Problem

I wrote some MS-Access code that I want to execute once a day.

I created a form a while back and included an entry like this:

  '#size' => 10

in several text fields of the form. Especially useful when you add a suffix:

  '#field_suffix' => 'Something'

But that would not do anything... I looked at the output of the form and it looked 100% correct. In other words, the input tag had its size="10" properly set. So the next step was to find whether some CSS code would be in the way.

You bet! The node.css file includes the following:

nice and ionice for Linux users

By default, a computer system gives each process the same priority level in regard to accessing your hard drive.

With newer versions of Linux, it is possible to use two other priorities: one where I/O is not primordial and thus you do not get it if anyone else wants it, and one where you want to work in realtime and have priority over anyone else.

This is achieved with the ionice command line (or corresponding kernel calls.)

This is particularly useful if you want to copy a partition to another and you know that it will take 20 minutes to copy everything... and thus the computer will be ...

/var is 99% full...

Problem

On Unix systems, you create partitions and assign them a folder such as /usr, /home, and /var. Many people like to put different things on different partitions. Very frankly, it is often complicated to do that, so if you don't have a real need, only break up the /home and /tmp folders from the rest. The /var is a good idea to break up if you use databases or very heavy logs. The /etc can be separate mainly for ease of backup.

Attacks by ZmEu or w00tw00t robots

Who is ZmEu?

An image showing Zmeu The 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.

I checked another server, and sure enough, that other server was ...

Trace PHP code with xdebug

xdebug

XDebug "logo" I'm very much working on Drupal and once in a while, I just have no clue what the code does... especially when there are callbacks that call callbacks in forever loops.

Unfreeze your Mouse when it Froze

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Who is ZmEu?

ZmEu Attack

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