Moved teh blog!

I've moved my blog onto www.nodeofcrash.com

I took a photo of this at the Adelaide Motor Show.
If you are a star wars fan like me, it's pretty cool.
Pity it's no on a Ford GT40 for something :p.

It's just one of those days........

I ran around like a monkey with it's ass on fire today. Everything was breaking at work.
AAARRRGHHHGHH...... OMG.......
There are days were I think the world conspires to make me go mad.
The solutions:

1.) Beer
2.) Beer
3.) More Beer

I started cycling to work as of yesterday. It's about 5.5km round trip. I get to work quicker on my bike than in my car. However, it tried to rain yesterday, and it rained today. So I think someone is playing a sick joke. To break the drought here in South Australia, I just need to ride to work, or another good one is wash my car. Always bloody rains after I wash my car.

Other than the gods trying to play silly games with me...... times are good.

The weekend I blew some dosh and watched 300 and Hot Fuzz.
"SPARTANS, CUP OF TEA!" ROAR!

If the world had been taken over by Spartans, daily conversations would be interesting to say the least. "SPARTANS, WHERE'S MY REPORT!"
"SPARTANS, UPDATE THE WEBSITE NOW!!"

Ah well, until later....

NRPE: Unable to read output

I've been working on setting up nrpe to allow a nagios server to execute check commands on another server.
From looking at NRPE, it seems to be a simple tcp server, a bit like a telnet server that receives a command, executes it on the host machine, and the sends the result back. NRPE also uses ssl encryption between the client and nagios server, so the communication seems quite secure.

============= =============
| Nagios Server | -> | Remote Server |
============= =============
check_nrpe -> nrpe server -> check_ping

So I've compiled nrpe from source to get the nrpe server daemon and the check_nrpe plugin.
As a note, I used the nrpe server daemon I compiled on the remote box, and I compiled nrpe on my nagios server. Then I copied the check_nrpe binary to the nagios plugin folder.
The point I'm making is, I didn't compile everything on one server, I compiled nrpe on both servers and used the server daemon on the remote box, and the check plugin on the nagios server.
Stops you getting compile / execute errors, due to package differences between the two servers.

Once I got nrpe up and running, I tried to use the check_nrpe script from the nagios server to connect to the remote server and run a check_users command. It would fail with NRPE: Unable to read output.
But if i sent a bogus command that wasn't defined in the nrpe.cfg file on the remote server, nrpe would come back saying the command didn't exist.
STRANGE indeed. That means NRPE is fine, the SSL is working, but something else is causing a problem.

In my /var/log/messages on the remote server I would find entries like this:
sudo(pam_unix)[15694]: authentication failure; logname= uid=0 euid=0 tty= ruser= rhost= user=nagios

These entries would appear after I ran the check_nrpe plugin from the nagios server.
It turns out, nrpe on the remote host, needs to execute the check commands as root. This makes sense as the data the check_users plugin needs, would only be available as root. Here sudo now gets involved.
So nrpe fires up an sudo command to run the nagios plugin to get say our check_users data.
The command would be something like sudo -u nagios /etc/nagios/plugins/./check_users -w 4 -c 8
If you were to goto the remote server, and do the following:
# su nagios (become the nagios user)
# sudo -u nagios /etc/nagios/plugins/./check_users -w 4 -c 8

After the sudo, you would see it request a password. As nrpe can't enter passwords, this is what is causing the error. It invokes the command, but can't complete it, as sudo wants a password.

To solve this, you need to edit the /etc/sudoers file.
Here is a good doc explaining it in detail:
http://www.chinalinuxpub.com/doc/www.siliconvalleyccie.com/linux-hn/sudo.htm#_Toc32905575

The short of it is, I uses visudo and added this to the sudoers file.
nagios ALL=(ALL) NOPASSWD: /usr/local/nagios/libexec/check_users

For some reason you have to add and entry for each file. With this done, nrpe will work correctly.

Cheers for now.

Error locking on node node1: Internal lvm error, check syslog Unable to deactivate logical volume "backup00"

I've got two servers at work running GFS and DRBD in primary / primary mode.
I added two drives to one of the nodes, to add extra storage for backups.
I created a new Logical Group (LG) called backup2 and a Logical Volume (LV) called backup00.
There were two 200Gb drives of Physical Volumes (PVs).
I created the LG using the normal lvcreate commands on the console.
For some reason though, because I was using GFS and clvmd on another share called /share, it decided to make the backup2 LG as clustered instead of a plain vanilla one.
Using the system-config-lvm tool I confirmed this.
Further more when I tried to remove /backup2 it I got and error:

Error locking on node node1: Internal lvm error, check syslog
Unable to deactivate logical volume "backup00"

Well node1 doesn't have a clustered lvm anyway. Very odd.

I'm using GFS and DRBD not the normal nmbd stuff.
I fixed this doing the following:

[root@node1 log]# lvmconf --disable-cluster
[root@node1 log]# lvremove -f /dev/backup2/backup00

Hottie Hottie Hottie, Oi Oi OI!

Anyone who says Aussie chicks are ugly, is a dumb ass.
These ladies were at the Adelaide Motor Show.

OMG Server Pwned!

The upstream provider for the company that hosts a website of mine was having some problems with throughput. The cause was found as shown above! Damn cats!

SPAM ..... grrrrr......

Many people say e-mail spam is a bad thing. But I must disagree on some points.

Most spam sent out in the past had exceptionally bad grammer and spelling mistakes. Not to mention being completely intelligible. Lately though, the spam has been getting pretty good. Fewer spelling mistakes and the grammer is much better. So we are improving peoples spelling and grammer skills!

The spammers have also started using text from books and articles, so it can be quite entertaining to read about the "foxes that paw and are hungry". I feel sorry for these poor foxes.

Further more, I am now the leading expert on all the different types of sex drugs out there. Viagra, Cialis etc. I also know the normal going rate for these drugs on a per pill basis, and the best place to purchase them.

What about those Morgage (or home loans) special rates and all the financial institutions that want me to confirm my details. Expanding the banking market as well!

The sad side is, in the last year I have had no less than 31 Uncles, Aunts and close family die in Nigeria and leave me a wealth of money in oil, diamonds etc. Including the number of times I have won the UK, US lotto, I should have more money than Bill Gates multiplied by two.
I unfortunately didn't have the $30 000 required in legal fees to deposit into a Swiss bank account to get the process going.

Lately alot of women have been e-mailing me wanting a good shag. What about a couple of "virgins in my are that want me bad". What more can a man ask for?

Okay, all jokes aside, spam is a very real problem. Of late I have noticed that spammers are targeting particular companies with relevant spam. For example my support email is getting e-mails titled "I have problems with e-mail" or some other relevant subject. This is a problem, as I have to open the mail and read this crap to make sure it isn't spam.

Anyway, enough ranting..... until next time.