The great Olympic spirit says that it's more important to participate then to win. That's is so wise and so true, but only when I finish within 8 hours of departure.
Lovely profiles of the mountains that have to be climbed. read more
From Bourg d'Oisans via the Croix de Fer and the Galibier to the Alpe d'Huez.. How boys become men. read more
Fedora ships with SELinux (Security Enhanced Linux) installed and in Enforcing mode by default. This can result in "Internal Server Error" messages when you attempt to access or install software.
See if SELinux is in Enforcing mode.
# getenforce
Put SELinux into Permissive mode.
# setenforce 0
The Nagios CGIs should work now. To make this change permanent, you'll have to modify /etc/selinux/config.
What?
Linux workstation with dual LCD monitors at 1920×1200 resolution on each screen. Need to have a single virtual Windows machine running on both monitors at full screen.
How?
1. Set-up Linux to use both monitors as single display using Twinview.
2. Install VMware Workstation. My installation version was 5.5.3 build-34685.
3. Install the virtual Windows machine.
4. Install VMWare Tool from the virtual Windows machine. Make sure VMware Tool is running.
5. Edit the virtual machine config, *.vmx file.
svga.maxwidth = “3840″
svga.maxheight = “1200″
svga.vramSize = “134217728″
Notes
* Width is 3840 because width of dual monitors, 1920+1920=3840.
* Default virtual graphic card ram size is 16MB. This is not enough to get the full 3840×1200 display. Need to adjust to higher value hence 134217728 @ 128MB.
The reason why I wanted to change the sizes of the partitions of one of my linux systems was the lack of space on the root partition. I'm running this linux system as a Virtual Machine (VM) using 256MB of RAM.
I could have choosen to enlarge the vmdk file (the virtual disk), but I didn't. I'll tell you why. In a VM you can have a swap partition of half the size of the amount of memory (VMware recommendation). As I sticked to the 'linux-out-of-the-box-installation' 512MB was used for the swap partition. So I decided to shrink the swap and use it to extend the root partition.
System used: Fedora Core 6 (but the procedure does not only apply to this linux flavour) and VMware server, though the latter is not quite relevant in this situation.
I’m giving Nagios a try, a very interesting Network Monitor system. It’s pretty cool stuff, but you have to take the time to get to know it. The setup and especially the configuration can get complicated.
The Nagios community is pretty lively and there are a lot of plugins you can download and use. The good thing is that there are a lot possible strategies on how to monitor you network. So, you just have to experiment and find out what you want, where to get it, how to install it and how to set it up. And when you’re finished, boy do you deserve a nice cool glass of beer. Better, do not wait drinking a beer ’till you’re finished, you’ll need it much earlier.
Article status: work in progress, last edit: januari 6, 2008
For a snmp server I used a vmware virtual appliance: cacti.
The clients I configured up till now are Fedora Core 6 environments. Windows will be added later on. read more
Files with the extension .tar.bz2 are compressed tarballs, a common way of sharing files on the internet. The compression rate is higher then that of a *.tar.gz or *.tgz file. Unpackig demands more CPU though.
You can extract files from a tarball using the ‘tar’ command, this will creat a new folder containing the files from the tarball.
# tar xvjf bestand.tar.bz2
Create a tar archive
# tar cvjf name_of_your_archive.tar.bz2 /path/to/directory
short explanation:
-x : extract
-c : create
-v : verbose
-j : type of compresssion used: bz2
-z: type of compresssion used: zip (*.tar.gz files)
-f : filename
scripts
A way to tar and zip files simultaniously using a script:
tar cvf – ./apl | gzip > /backup_dir/apl.tar.gz &
tar cvf – ./bin | gzip > /backup_dir/abin.tar.gz &
tar cvf – ./dualpath | gzip > /backup_dir/adualpath.tar.gz &
File systems are part of our everyday lives. We store and retrieve data constantly, but rarely do we think think about how each file system works. Perhaps that’s as it should be: Linux supports many different kinds of file systems, and most are mature and robust. For example, the Linux kernel supports the traditional Ext2 file system (among others), several cluster file systems (Lustre, GFS, GPFS, and CXFS), and also includes no less than four journaling file systems that have been proven time and again in production server environments, where high throughput and near-perennial uptime is essential. (For additional information on journaling file systems, see the October 2002 Linux Magazine article titled “Journaling File Systems”, available online at http://www.linux-mag.com/2002-10/jfs_01.html.)
But journaling file systems need not be limited to servers. Journaling file systems can also benefit client machines, where performance and reliability is often just as critical. However, the jobs assigned to a workstation and the demands placed on a server are radically different. To get the best high throughput and high uptime requirements performance out of both, you have to tune each configuration to suit. Let’s use the open source dbench benchmark (http://samba.org/ftp/tridge/dbench/) to tweak and measure a number of different workloads and see how a little work can yield big results.
(This article taken from the www.linux-mag.com website, author Steve Best)
