Instalar y configurar un servidor usando Fedora es una tarea sencilla y bastante entretenida. A lo largo de dos post explicaré paso a paso cómo instalar un servidor completo, tanto FTP como HTTP. Pero antes de empezar, ¿qué es un servidor?
En informática, un servidor es un tipo de software que realiza ciertas tareas en nombre de los usuarios. El término servidor ahora también se utiliza para referirse al ordenador físico en el cual funciona ese software, una máquina cuyo propósito es proveer datos de modo que otras máquinas puedan utilizar esos datos.
En la primera parte explicaré como instalar VSFTPD (Very Secure FTP Daemon), considerado como la opción más segura para crear un servidor de este tipo. Algunos ejemplos de servidores que usan VSFTPD:
Para empezar, instalaremos los paquetes que necesitamos. Para ello nos logueamos como root y escribimos:
yum install vsftpd
Ahora ya tendremos nuestro servidor FTP instalado. A continuación lo configuraremos y ya podremos empezar a compartir datos con él. Vsftpd tiene dos archivos de configuración, ambos guardados en /etc/vsftpd/
En primer lugar abriremos el archivo vsftpd.conf, donde se encuentran la mayoría de las opciones que podremos modificar.
Si usas Gnome | gedit /etc/vsftpd/vsftpd.conf
Si usas KDE | kwrite /etc/vsftpd/vsftpd.conf
Os recomiendo que leáis con calma todos los parámetros y los modifiquéis para que se adpaten a vuestras necesidades. A continuación citaré los más importantes a tener en cuenta.
Si el valor es YES cualquier persona podrá acceder al servidor. Si es NO, sólo los usuarios autentificados podrán acceder.
Con esta opción podemos permitir la entrada a usuarios locales o no
Si queremos permitir la escritura en nuestro servidor, escribiremos YES. Si por el contrario, queremos que sea de solo lectura, pondremos NO.
Aquí escribiremos un mensaje que será mostrado cada vez que un usuarios accede al servidor.
Se utiliza para determinar la máxima velocidad de transferencia a los usuarios anónimos. Se utilizan los bytes por segundo como unidad.
Aquí podremos determinar el número máximo de conexiones simultáneas a nuestro servidor FTP.
Igual que el anterios pero para limitar las conexiones que usen la misma IP. Lo lógico es poner el mismo tope que el anterior parámetro. Esto nos servirá para limitar el número de conexiones simultáneas de personas que usen un mismo Proxy, por ejemplo.
Ahora que ya tenemos todo configurado (estos son los parámetros básicos, pero hay muchos más) sólo tenemos abrir los puertos en el cortafuegos y arrancar el servidor. Para ello vamos a Sistema – Administración – Cortafuegos y en servicios confiables seleccionamos FTP. Aplicamos y cerramos.
Ahora abrimos una terminal, nos logueamos como root y escribimos:
service vsftpd start
Además si querermos que arranque durante el arranque, escribimos:
chkconfig vsftpd on
Listo!! Ya tenemos en marcha nuestro servidor FTP. Para comprobar que funciona, abrimos el navegador y escrbimos en la direccion:
Ahora sólo queda empezar a compartir archivos. Para ello tened en cuenta que la carpeta en la que hay que guardar los archivos para que sean visibles en nuestro servidor es /var/ftp
Fuente | El blog de Iyan
When I was fist seen this command, I was thinking ohhhh god why I haven't seen this command long time back, this could have make my life much more easier.
tail -f /var/log/messages
The main advantages of tail -f is that, you can monitor logs real time it will keep on appending logs as it goes, but what if I have found one error and want to look back what went wrong, I have to quit the tail and open the file in VI or with less.
There comes the advantage of less +F, you can monitor logs real time it will keep on appending logs as it goes, and if I found error I can execute ctrl+c to stop appending real time log and can go back and check what went wrong, once I verified and can again start appending log by executing capital F
less +F /var/log/messages
This does the same thing as tail -f but it will also show the entire file, just press ctrl + c to navigate around the log file. When you want to view the log in real time again just type a capital F.
I was syncing two Linux hosts, just need to copy data between them. I don't need and neither don't want to install Samba as a Service for a quick sync, RSync was my preferred method.
RSync is very easy to use and quick but in this case I don't either want to install RSync service daemon as well on the destination machine (the machine with data to transfer), so I've opted for rsync through ssh tunnel without a service installed.
Here's a quick sample:
- You've to transfer data from remote host machine (name: "oldhost")
- You've to copy data into another machine (name: "newhost")
- You don't want to install/configure rsync daemon on these two machines
- You've at least ssh server access to "oldhost" from "newhost"
- You've at least rsync program installed on "newhost"
Ok, don't configure rsync daemon on these two machines, just login to "newhost", go to target directory (the directory where you'd like to have data copied) and issue a command like this:
newhost:/target# rsync --verbose --recursive --copy-links -perms --owner --group --compress --specials --stats --devices --times --delete -e "ssh -l root" oldhost:/source/ .
Please substitute /target with your target directory on newhost, /source with your source directory from oldhost, root with your favorite username on remote host
This command uses rsync through ssh shell on remote host and copies data from there to local host on specified directory (current directory as latest "." on command reported)
You can substitute "." with local target directory as needed
In this way rsync is just used without the service (rsyncd), as a new blog I can create few easy steps for rsyncd configuration if you need it.
I always use this method for one shot synchronization, when your rsync operation are scheduled of programmed periodically it's better to use rsyncd service, this is my favorite backup system
Glad to read your comments
Andrea Ben Benini
This quick post shows you how to create a samba share for a network, every user is forced to a specific username and each file belongs to this username. This is useful when dealing with public folders for some sort of exchange between users in a network
Read/Write access to everyone for directories and files, this is a tipical configuration for a swap area
Check it out:
comment = Public folder for my network
available = yes
browseable = yes
path = /home/public
guest ok = yes
public = yes
writable = yes
write list = *
force group = commongroup
force user = commonuser
create mask = 0644
directory mask = 0755
printable = no
A while back I wrote about using Apache as a dynamic reverse proxy
. Anyone who has done even minimal research into web servers knows that Apache is the swiss army knife. It trys to be everything for everyone, and like a swiss army knife may not be as good as a more refined too at least as far as efficiency is concerned. (Read More)
Installing Oracle on Linux
Create Users and groups
Creating directories for installing oracle
Change Kernel Parameters
Create User and groups
#useradd –m –g oinstall –G dba oracle
Creating directories for installing oracle
#Mkdir –p /u01/app/oracle
#Chown –R oracle:oinstall /u01/app/oracle
#mkdir -p /u02/oradata
#chown –R oracle:oinstall /u02/
Change Kernel Parameters
# vi /etc/sysctl.conf
kernel.shmall = 2097152
kernel.shmmax = 536870912
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 65536
net.ipv4.ip_local_port_range = 1024 65000
oracle soft nproc 2047
oracle hard nproc 16384
oracle soft nofile 1024
oracle hard nofile 65536
session required /lib/security/pam_limits.so
if [ $USER = "oracle" ]; then
if [ $SHELL = "/bin/ksh" ]; then
ulimit -p 16384
ulimit -n 65536
ulimit -u 16384 -n 65536
# cd /opt/database
Application path Ã”Ã‰â€ /u01/app/oracle/product/10.2.0/db_1
Global database (gtldev.localdomain sid gtldev)
Unicode standard utf-8 AL32F8
File system storage ( /u02/oradata/
Do not enable backup
After installation run two scripts
# cd /home/orainventory
WebServices Wars: "The Phantom Menace": Creating the WebService WSDL file
Now if you've followed the introduction "WebServices Wars: Creating a basic webservice using Eclipse, php and apache
" you're now ready for Episode I
This webservice saga begins with the base of every good project: the planning and design phase.
Here's what I'm going to do:
- Create a WSDL definition file for the new service, it will be called sample.wsdl, it will be accessible from the following URL: http://my.website.com/sample.wsdl
- Create a webservice server called sample.php it will provide sample.wsdl implementation, it will act as a service for etherogeneous applications requiring for it from this url: http://my.website.com/sample.php
- Create a webservice client file, this is just for seeing some output and understand how php can access services, it doesn't matter if you plan to use php on the backend server or not. The url could be http://my.website.com/client.php
- Make some considerations on debugging techniques and caching in development environments and production areas
This example will use SOAP techniques, SOAP is quick and easy to use, PHP already provide native SOAP classes, they're fast and well written in low level, not an external php library for SOAP. Personally I don't like NuSoap or third party libs for PHP, native support is reliable, fast, documented and stable.
I'll assume you already know what a webservice is, what you can do with it and how to use it in a real environment, please read this intro if you need it, it's a nice starting point.
As W3C suggests you can create a webservice with or without WSDL definition file, but if you're planning a big project or you just want to make things easy and well documented I suggest you to use WSDL files from the beginning, it's more easy to understand internals and speeds up your programming
Our sample webservice will provide these methods:
These two methods are just samples to understand how you can use them, some sort of Hello World service.
Now we need to write the webservice definition file (sample.wsdl), this file defines these two methods and their interfaces, the webservice url and other useful things, more documentation on WSDL can be found here from the official site.
You can obviously write this sample by hand, it's not difficult but when you do it the first time you can run into roubles if you don't know W3C documentation well. If you use Eclipse you already have a powerful tool called "The WSDL Editor", this amazing toy can create your WSDL files from a GUI interface in few minutes without orrying too much about WSDL internals, it's fast, intuitive and easy.
I'll suggest you to install the Eclipse Web Standard Tools (WST plugin) as well as WSDL tools and editors (WSDL), hese packages provides you HTML validators, html code completition, debugging tools, editors (web and wsdl) and lot of other useful functions.
Next episode will require PDT (PHP Development Tools) (Eclipse PDT plugin) so if you collect eclipse and these extensions you'll have a complete PHP/WebServices development tool, check out requirements from introduction article
When you're a beginner and you want to create a WSDL file with Eclipse you're probably looking for something good, already working and editable with WSDL Editor with no hassles, when I was googling around for wsdl files the first time I've found a lot of non-W3C compliants, malformed, wrong files and I've lost a lot of time to understand where errors were located, here's my sample for you.
According to my example and the two methods planned above here's the good W3C Compliant WSDL file:
Create a new wsdl file (Eclipse: File, New, File) and name it sample.wsdl
Save the file and close it so you've this working sample.
When WSDL Editor is installed you can directly open it in GUI mode (WSDL Editor Itself),
it's easy to read, maintain, rewrite and modify, take a look at the following picture:
Amazing, isn't it ?
With this tool you can see in a nice gui mode your webservice, easy for a newbie and for an expert as well. When you select an item you can select and modify its properties in the properties window, take a look at my sample data and see where they are located
If you click on the arrows in the right side you can open another window with input parameters for the two methods, take a look at the picture below
Here are the methods
Play with the file, it's a good starting point for future projects, it was created with Eclipse 3.4 Ganymede and latest tools synced from Eclipse central repository, you can easily open it with outdated eclipse versions or without WSDL editor as well; Eclipse doesn't have backwards compatibility issues (like other IDEs)
When finished just put this file in your webserver and make it accessible from outside, in my example this file it's located in /var/www/htdocs/sample.wsdl, according to my current Apache2 config this file is available from the following url: http://my.website.com/sample.wsdl, sample.php (webservice server) and client.php (webservice client) will refer to this url for getting WSDL properties
For a closer look at WSDL Editor take a read at the WSDL Editor Documentation, it's THE starting point for everything, refer to W3C for reliable SOAP and WSDL documentation
Stay tuned for the next episode...
Introduction: "WebServices Wars: Creating a basic webservice using Eclipse, php and apache"
Episode I "The Phantom Menace": Creating the WebService WSDL file"
Episode 2 "Attack of the Clones": Creating the WebService php Server (coming soon)
Here I am,
That's a lot of time since my last blog, well, I was quite busy with something else (still have my private life ok ?) but now I'm back again with WebServices, PHP, Eclipse, Apache.
A lot of folks are asking me about some sort of short howto/sample/easy doc for dealing with webservices and php, there's a lot of information spread all around the web so I've decided to collect information from my projects and write down some notes for a quickstart howto with webservices and php.
Now if you like to write down everything from scratch you can surely do but if you're working on a big project you're surely already using an IDE of some sort.
I've tried a lot of different commercial and open source IDEs and after a lot of evaluation I've choosen Eclipse because it's mature, stable (quite), reliable, studied for big enterprise class projects ...and I've a fast and huge pc with a ton of ram on it.
Eclipse is reliable, well known and supported, one of its major drawbacks are about system resources, it eats a lot of ram but if you've a recently updated PC with a good linux distro and a good amount of ram you can surely use it and you'll never go away from it. PHP folks will surely install PDT (http://www.eclipse.org/pdt/): PHP Development Toos Project for Eclipse, it's now a mature plugin for eclipse, reliable and suited for php professional development.
I don't wanna bother you about details on configuring eclipse/pdt/apache/php and so on (maybe another blog argument ?) I'll assume you've this configuration :
- Eclipse and PDT up and running in your workstation, don't care about operating system but of course if you're using linux it's better :-) (gentoo linux like me even better). But I really don't care, just need Eclipse up and running
- Web Tools Platform plugin for Eclipse, not really required but useful, it provides: web page editor inside Eclipse, WSDL editor, HTML Validators. WSDL editor is very important if you wish to create webservices with a GUI interface, if you're mastering xml/soap/rpc files and you want to write them on your own you're free to do this.
- A webserver with php extension installed, Apache2 and PHP5 are used in this sample but every webserver suitable for php is good (here again, apache2 and php5 are better than everything else)
- Common PHP knowledge and some Object Oriented programming skills, here used for these samples
- Basic SOAP and WebServices knowledge, at least you need to know what they can do and what is this technology for, later you'll better understand soap after reading samples
This blog is just an intro and a "bill list of materials" before getting started
This is an intro, next article will be the first "hands on" with eclipse and WSDL creation
As usual feel free to ask and write down some comments when needed, hope it helps
Episode 1: WebServices Wars: "The Phantom Menace": Creating the WebService WSDL file
Andrea Benini (Ben)
In two earlier articles
, we discussed ways to make your website load faster. Another issue many users face is the sometimes painfully slow speed of email. "What do you mean, you haven't gotten it yet? I sent that email over an hour ago?" Does this sound familiar? There are several steps that must take place between your hitting the "send" button and the recipient viewing your message. A delay in your email's journey can occur at one or more of these steps.
Part 1 of this article will address ways to optimize the speed of your network connection, in addition to the website-specific tips we focused upon in "9 Tips to Make Your Website Load Much Faster." These suggestions may increase the speed at which you can send and receive email, as well as improving the performance of your web pages and other file transfers.
1. Problem: Delays caused by the distance between you and your web server.
Solution: As with your website, you can remove one potential cause of slow email by selecting a web hosting provider that has a data center near you. This is the single most important thing you can do to increase your email speed.
While you can't control how long it will take your email to reach your recipient once it leaves your email server, or how long a message from another person will take to reach your email server, you can minimize the time it takes incoming emails to get from your server to your mailbox, and vice versa for outgoing emails.
For example, let's say Tony Traceroute, an employee in your Newark office, wants to send a large file - a CAD diagram of his new widget design - by intraoffice email to Patty Ping, who works just down the hall from Tony. If your company's server is located in Los Angeles, then when Tony hits the send button, his email will travel all the way to sunny California, through whatever routers and packet switches it encounters along the way, then all the way back to Delaware - an odyssey of some 5,000 miles - before it arrives in Patty's inbox! It might have been faster if Tony had just printed out the diagram and walked down the hall to drop it off!
The bottom line: if you rely heavily on email in your business, choosing a web hosting company with a nearby data center may save you a considerable amount of time and money.
2. Problem: Overuse of server capacity on shared servers. Every user on a shared server is allocated a certain amount of bandwidth and other server resources. When a user goes over this limit, it can slow down the other accounts on the server.
Solution: Make sure your web hosting company has policies in place to manage excessive usage by individual clients on its shared servers. Some hosting providers automatically suspend accounts that use excessive resources. While this works, the best way for a web hosting company to handle these accounts is to migrate them to a separate server where they can't negatively impact the performance of other shared accounts. If you're on a shared server, ask your web hosting company how they handle such accounts.
In addition, talk to your web hosting company to make sure that they aggressively combat spammers and other system abusers who are likely to consume system resources and slow down your website and email.
3. Problem: Your email may encounter a bottleneck if there is an issue with the bandwidth provider that your web hosting company uses. Most large web hosting companies have partnerships with multiple major bandwidth providers to ensure this does not happen. Smaller hosts may not be able to afford these partnerships, leaving you susceptible to a slowdown.
Solution: Find out what types of ISP partnerships your web hosting company has. You can run a simple trace route test to see what partnerships your hosting company has with bandwidth providers. Look for major communications companies (Tier 1 or highly reputable Tier 2 providers) such as MCI-Verizon, AT&T, Mzima, Level(3), Global Crossing, etc.
Ideally, your web hosting company should have a variety of bandwidth partners. That way, your web host will be able to reroute email data quickly if one of the bandwidth providers goes down. If your web host does not have major partnerships, it may be in your best interest to look for a web hosting company that does.
4. Problem: Connection problem on your end - If you're using "home-grade" equipment, and you think your connection may be slow, try running a speed test at a site such as speedtest.net. Sometimes modems and routers will go out of sync after being powered on for weeks or months at a time. This is especially true if you are using a modem and wireless router combination.
Solution: Try refreshing your connection. Simply power down both your modem and your router. Then turn the modem back on, wait a few minutes, and turn the router on (the order of these steps is very important).
If this doesn't increase your connection speed, notify your cable or DSL provider. They will test your connection speed, and they may be able to optimize your connection from their operations center.
• Be sure that you are located as close as possible to your web hosting company's data center.
• Ask your provider about their excess usage policies if you are hosted on a shared server.
• Make sure your web host has partnerships with the top bandwidth providers.
• Conduct basic tests with your internet provider and on your own home router/wireless setup.
Part 2 of this article will focus on optimization techniques that are specific to email. We'll look at issues that can slow email such as spam, misconfigured spam filters, bloated emails, and reverse DNS lookup - and what you can do to address these problems.
Recently I came across unexpected results when trying to order a table by stored IP Addresses.
mysql> select ip from table order by ip desc;
The results looked like this:
| 10.5.0.91 |
| 10.5.0.90 |
| 10.5.0.9 |
| 10.5.0.89 |
| 10.5.0.88 |
| 10.5.0.81 |
| 10.5.0.80 |
| 10.5.0.8 |
| 10.5.0.79 |
| 10.5.0.78 |
Here's the quick fix ...