Tar.gz

Here are some common way to create your archives.

#Creates simple targetfile.tar without compression.
tar cvf targetfile.tar sourcedir/*

#Zip everything beneath sourcedir to targetfile.tar.gz
tar cvzf targetfile.tar.gz sourcedir/*

#Bzip2 everything beneath sourcedir to targetfile.tar.bz2
tar cvjf targetfile.tar.bz2 sourcedir/*

Parameters explanation:

• c  or –create create a new archive
• v or –verbose  verbosely list files processed
• z or –gzip  usage of gzip compression (or also decompression, context dependent)
• j or –bzip2 usage of bzip2 compression
• f or –file  use archive file

Alternative with pipe usage:

tar -cf - sourcedir | gzip -c > filename.tar.gz

Zip

Some examples

#Zip every file in current directroy to file.zip.
#But hidden files like (.htaccess) are not included.
zip file.zip sourcedir/*

#also includes hidden files.
zip file.zip sourcedir/* .*

The above examples include directories but still not their content recursively, -r option is required.

#Adds all files and directories recursivly.
zip file.zip -r /sourcedir/*

#Same as abowe with addtional enryption and password lock.
#Password is prompted on the terminal.
zip file.zip -re /sourcedir/*

#Splitts creted archive to parts not bigger than 2 Gigabytes.
zip -s 2g -r test.zip ./*

Hope that helps someone.

Happy new year!!!

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1. download and prepare.

Start by download  currently available version (7.0.2) of the JBoss 7.

#Web Profile version download.
wget http://download.jboss.org/jbossas/7.0/jboss-as-7.0.2.Final/jboss-as-web-7.0.2.Final.tar.gz

Extracting files to the final location using tar.

<pre>tar zxvf jboss-as-web-7.0.2.Final.tar.gz -C /usr/local/

Now your JBoss 7 is placed inside /usr/local/jboss-as-web-7.0.2.Final/.I dont’t like that name.  It’s just cosmetics, but i prefer to rename the last part ot the path.

cd /usr/local/
mv jboss-as-web-7.0.2.Final/ jboss-7.0.2

Now important things. Some basic security and right management. I suppose  you don’t want to start your JBoss with root rights.
Therefore we need to create new user and new group named  jboss. Make them owner of your JBoss stuff.

addgroup jboss
useradd -g jboss jboss
chown -R jboss:jboss /usr/local/jboss-7.0.2/

Your jboss 7 is almost installed now.

2. Configuration and first test.

Start your brand new  Jboss 7 server with:

sudo -u jboss sh /usr/local/jboss-7.0.2/bin/standalone.sh &

Now it  is testable on your local machine with http://localhost:8080.
But! maybe you trying to install that jboss on remote machine and want to access this installation remotely. I that case you need to enable remote interface of your JBoss. I assume we start by standalone configuration, so  you have to edit /usr/local/jboss-7.0.2/standalone/configuration/standalone.xml file. The easiest way is to  find <interfaces> section and replace the 127.0.0.1 address with <any-address/>

<interfaces>
   <interface name="management">
     <any-address/>
     </interface>
   <interface name="public">
    <any-address/>
   </interface>
 </interfaces>

Beware with this configuration you expose also the management console to the public. The console is bounded to interface named=”management” by default.  In production environments you have to put more attention to this. but now you can access your jboss from anywhere.

3. Jboss as Service

Now we have a basic configured JBoss, but i want to maintain it as a service. Unfortunately Jboss archive has no predefined init.d scripts, so i have to to it on my own. But this is not a big problem, just straightforward following some Debian conventions and useful scripts.

Ok, let’s create jboss maintenance script.

touch /etc/init.d/jboss
chmod 755 /etc/init.d/jboss

Ready! Now put following inside.

#!/bin/sh
### BEGIN INIT INFO
# Provides: jboss
# Required-Start: $local_fs $remote_fs $network $syslog
# Required-Stop: $local_fs $remote_fs $network $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Management of JBoss AS v7.x
### END INIT INFO

#Defining JBOSS_HOME
JBOSS_HOME=/usr/local/jboss-7.0.2

case "$1" in
start)
echo "Starting JBoss AS7..."
sudo -u jboss sh ${JBOSS_HOME}/bin/standalone.sh &
;;
stop)
echo "Stopping JBoss AS7..."
sudo -u jboss sh ${JBOSS_HOME}/bin/jboss-admin.sh --connect command=:shutdown
;;
log)
echo "Showing server.log..."
tail -1000f ${JBOSS_HOME}/standalone/log/server.log
;;
*)
echo "Usage: /etc/init.d/jboss {start|stop|log}"
exit 1
;; esac
exit 0

This file is ready to use. You can use it self for manual start and stop of your jboss, you also can follow the server.log by using “log” parameter.
But let’s make it to the end, as an automatic starting service. It’s easy with update-rc.d script:

update-rc.d jboss defaults

Now your ready and your JBoss will be shutdown on machine shutdown and it should start on machine start-up.

Of course this is not the only way to start using JBoss 7. Your ideas are welcome!

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wget http://download.oracle.com/otn-pub/java/jdk/7/jdk-7-linux-x64.tar.gz
tar zxvf jdk-7-linux-x64.tar.gz -C /usr/lib64/jvm/

Then we have to do some configuration.
Debian Linux has useful script to maintain different version of one programs like java called update-altenatives. So i simply use this.

update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0/bin/java 1065
update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.7.0/bin/javac 1065

Where 1065 is a given priority.

To check my installation i use –config paramter

update-alternatives --config java
#this prints:
There are 2 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                      Priority   Status
------------------------------------------------------------
* 0            /usr/lib/jvm/jdk1.7.0/bin/java             1065      auto mode
  1            /usr/lib/jvm/java-6-openjdk/jre/bin/java   1061      manual mode
  2            /usr/lib/jvm/jdk1.7.0/bin/java             1065      manual mode</pre>

And because 1065 is higher than 1061, the fresh installed java 7 will be used by default on my machine

java -version
#prints:
java version "1.7.0"
 Java(TM) SE Runtime Environment (build 1.7.0-b147)
 Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)

Hope this save somebody some setup time.

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The pictureon the right (klick to enrange)  shows  how Ubunto boot process is going on my 5 years old Thinkpad T60. Bootchart utility does such charts automatically. If you interestiong how easy it it to enable such bootcharting read below.

Installing bootchart

See how to install bootchart logger on ubuntu, and other linux distributions.

Yo need bootchart and, pybootchartgui

apt-get install bootchart

apt-get install pybootchartgui

That will automatically add bootchart logger to your grub configuration . Restart your machine and look for an image file in /var/log/bootchart directory.

Disabling bootchart

Someday you maybe wan’t to disable bootchart again.

To disable it just throw it out of your GRUB configuration. On GRUB 2  (which is default on ubuntu since v. 9.10) you have to change file /etc/default/grub.

Change line

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash bootchart=disable"

and then run:

sudo update-grub

You done.

On GRUB 1 you have to edit /boot/grub/menu.lst.

Any comments?

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• 

Step 1: Install subversion

If subversion is not installed, install it with:

$apt-get install subversion

Step 2: Create repository

Prepare place for repositories. Standard good palace is /var/svn but i personally prefer /srv/svn. (What is your favorite? Why?)

#create directory
$ mkdir /srv/svn/
$ mkdir /srv/svn/java

Create File system based repository (FSFS) or DB based. Today state of the art are FSFS repositories.
So just use FSFS based repositories, believe there are many advantages compared to Berkley DB.

#create FSFS repository
$ svnadmin create --fs-type fsfs /srv/svn/java

Step 3: Access control

At this point subversion is running and it’s best time to think about user access rights to repositories.
First create new group for svn users and assign it to your repo. In my case I’ve defined one repository special for java projects so i wanna use special group for that.

$ addgroup svnjava     # create new group for java repository
#apply that group to the repository location
$ chgrp -R svnjava /srv/svn/java

Now change authorization of the group on desired repository.

$ chmod -R g+rw  /srv/svn/java       # group mebers my write
$ chmod -R o-rwx  /srv/svn/java      # other not.
$ chmod g+s /srv/svn/java/db         #  this ensures log-write

Create new linux users (if not ready) and him to the group

$ useradd aho #new user
$ adduser aho svnjava #assigning user to the group

Soon user aho will be able to access subversion repository, but first we have to proceed with the next step.

Step 4: Additional configuration

Repository needs to be configured a little to be useful. Open conf/svnserve.conf in you new repository
$ nano /srv/svn/java/conf/svnserve.conf
and remove comments (#) from these lines.:
anon-access = read
auth-access = write
realm = My Java Repository
save file.

Step 5: Umask!

After previous steps we have an repository which is suitable for one user but concurrency usage by many users will run into problems by default umask 022.
So the common solution is to make a wrapper invocation of subversion. Let's create an wrapper step by step.
Find where you subversion i currently installed with the following command.
$ which svnserve
#returnes me
#/usr/bin/svnserve
Now rename original svnserve to svnserve_orig, create new file named svnserve with following:
$ mv /usr/bin/svnserve /usr/bin/svnserve_orig #renamin' of orinignal svn
$ touch /usr/bin/svnserve # create new wrapper
$ chmod 755 /usr/bin/svnserve #set rights as original
Now add following to new wrapper script svnserve
#!/bin/bash
umask 002
/usr/bin/svnserve_orig $*
So we're done!
P.S. See how easy you can move you repository or do backups

UPD! Subversion with Mod DAV

On default svn is not called by a superserver line xindet .d. But it does not matter if you prefer svn+ssh access. In this case you access the svn machine directly trough ssh and call svnserve commands virtually direct on remote machine, so don't need to configure anything more.

But, if you have problems with firewalls, witch clients software or just want to have more flexibility, you may be interested in accessing you repository through http:// or https://. In dies case mod_dav commes in to play.

Mod DAV step by step

1) Install Apache server if not already done it.

$ apt-get install apache2

2) Configuration.

Normally Apache package has all of the common mods including mod_dav_svn. Debian distribution has a package libapache2-svnwhich registers needed modules for you.
So just install it:
$ apt-get install subversion libapache2-svn
Now all needed modules are registered to Apache. You just have to provide a concrete configuration for your svn repository.
 Here is one simple example how i do it i my case. Works fine.
# Check the location of dav_svn.conf then just
# copy all following lines to your shell and hit enter.
#  conf will be appended to dav_svn.conf
echo "
DAV svn
SVNPath /srv/svn/java

AuthType Basic
AuthName "My Java Repository"
AuthUserFile /etc/apache2/svn.pass
Require valid-user

" >> /etc/apache2/mods-enabled/dav_svn.conf
This configuration is self-explainable.

• SVNPath = Path to repository location,
• <location /svn/java> = is path in acces URL, e.g. http://mydomain/svn/java/
• AuthType Basic = means password based access
• AuthUserFile point to a file with user and passwords.

Red more about Auth Modulif interested in advanced configuration

3) Now you only need to create some user an passwords.

# -c option is used to create new password file.
# Don't use it if create scond user.
$ htpasswd -cm /etc/apache2/svn.pass aho

If you try open it now, you’ll run in to an error. It’s because now the svn repository is accessed by a user of Apache server. Default it would be www-data.

4) So just give him some more rights.

$ adduser www-data svnjava

5) reload apache configuration.

Manual approach

If you are not able to use  libapache2-svn, then you have to register required modules manually:
#make sure your apache is ins /usr/lib64/apache2. adapt path otherways.
$ echo "LoadModule dav_svn_module  /urs/lib64/apache2/modules/mod_dav_svn.so
LoadModule authz_svn_module  /urs/lib64/apache2/ modules/mod_authz_svn.so"
>> /etc/apache2/conf.d/svn.conf
More information and examples can be found in SVN Book in server-conf chapter.

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lsof stands for “list open files”. So actually it shows all files used by some processes of a system. That command exist on most of and on different Linuxes and Unixes.
It bases on architecture of a kernel which causes evety procces to hold it used files in /proc – (a virtual file-system).  A typical hierarchy wold look like:

/proc/process id/fd/file descriptor

In the absence of any options, lsof lists all open files belonging to all active processes of a system. But that is to much for most cases, because many of cases are networkrelated. An if you consider that sockets are files in linux we can use lsof to search fo them.

Examples lsof sockets

The interesting option here is the -i option and it should be followed by the Internet address which is specified in the following form:

[46][protocol][@hostname|hostaddr][:service|port]

4 and 6 stand for ip protocol versions, the rest should be self expanded. So now i think is best time to provide some examples. Here they are:

Show all open connections

 lsof -i

Show all open TCP connections

lsof -i TCP 

Show open TCP connection on on secure ldap port 636, http 80 and UDP protocol range

            lsof -i TCP:636
            lsof -i TCP:80
            lsof -i UDP:3000-3025
         

Show LDAP incoming connections

lsof -i TCP@192.168.0.1:636 ()
#java  890 root  18u  IPv6 8332031
#TCP myserver.com:42936 myserver.com:ldaps (ESTABLISHED)

Who use SMTP?

         lsof -i :25
         #COMMAND  PID USER   FD   TYPE        DEVICE SIZE/OFF NODE NAME
         #sendmail 401 root    5u  IPv4 0x300023cc141      0t0  TCP *:smtp (LISTEN)
         #sendmail 401 root    6u  IPv6 0x3000243c200      0t0  TCP *:smtp (LISTEN)

Further useful Examples of lsof

-c option allows to see what files are open by a particular command.

lsof -c mysq
lsof -c ruby

See what files are open by a particular device or a file

lsof /dev/cdrom
lsof /tmp/obscure.lock

See what files are opened by a user shuron

lsof –u shuron
#vi   5200 shuron txt REG 3,1   242601 245773 /bin/vi

Additional info

And at last use -r option for monitoring. Here is example of periodically (every 10 seconds) refresh of connection status for a concrete application started as php.

lsof -r 10 -c php -a -i :1521

It gives periodically all 1521 port connections. 1521 is typical Oracle DB connection port, so that example may serve you as base for script that monitors connection growing of your PHP applications.

So the last on is interesting also it uses the -t parameter which causes lsof return only a Processor id of a file using application. So following command allows you to kill all application that are using provided file.

kill -9 `lsof -t /tmp/obscure.lock`

References: Lsof Man

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Here some hardware details:

• Intel Core Duo (T2400 -1,83 Mghz)
• 1 Gb RAM
• 60 GB 5400rpm  hard drive

An here are starttimes on two Systems (in seconds):

As we see Windows takes 1 minute from OS-Selection dialog till User-login dialog, whereas Ubunto takes  only 24 sec. Ok, windows checks  “security chip” (what it exactly means and why it so good for me i don’t know)  and that takes considerable time and i’m unsure whether Ubunto do something like this, but however i can’t change it.

On a graph we see also, that for the rest of “loading work” from login till first page appears in firefox browser windows takes more time again. It takes 95 seconds whereas Ubunto need only 19!  I was clicking on browser Icon as soon it appeared and was “clickable” and waited till pre-selected starting page (google) appears.

Of cause tas is not very strict measurement so maybe I’ve lost one or two seconds somewhere, who cares if

• Ubunto takes 24+19 =43 sec
• Windows takes 60+95 = 155 sec

till i can use my typical day by day application. So now i can save more than a one and halfe minute of my life on every start of a system.

Respect Ubuntu, keep on going!

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Here are configurationsteps for mail-sending with Exim and Googlemail account (google Apps accounts work the same way too).

1. first of all we need working Exim. If not installed – install exim4.

   $ apt-get update
   $ apt-get install exim4
   

2. Configuration should start after the installation. However you can start configuration of exim every-time with

   $ dpkg-reconfigure exim4-config
   

3. Answer the questions of configuration wizard. The important one is.
   a general type of mail configuration. Choose “sent by smarthost”
   if you wanna use the ability of e.g. Googlemail account. Then SMTP with dynamic IP would be difficult
4. answer other questions
   • Provide a System Mail Name: e.g. mycompany.com
   • Provide IP addresses to listen on for incoming SMTP connections
     User 127.0.0.1 if you don’t want only send mail from local machine and nothing for all IP’s.
   • Provide Machine handling outgoing mail for this host (smarthost): smtp.gmail.com::587

   Other parameter are not so important for a start. However read more about debconf questions and other configuration if you like.

5. Now it’s time to provide credentials information of your gmail account. Therefore you need edit /etc/exim4/passwd.client file with your favorite editor.
   Insert that for Standard or google app account but replace with valid mail and password.

   gmail-smtp.l.google.com:yourYourMail@googlemail.com:yourPass
   *.google.com:yourYourMail@googlemail.com:yourPass
   smtp.gmail.com:yourYourMail@googlemail.com:yourPass
   

6. Make sure /etc/exim4/passwd.client belongs to user root and group Debian-exim which is normal so on my Debian. If not, run that command:

   $ chown root:Debian-exim /etc/exim4/passwd.client
   

7. Actualize the whole configuration with:

   $ update-exim4.conf
   

   Your ‘re done!

Now it’s test it with.

echo "Server Mail Test Message " | mail -s "Just Test" SomeMail@someDomain.org

Watch logs:

$ tail -1000f /var/log/exim4/mainlog

When you see something like this. Everything should vent perfect.

2010-02-14 23:00:26 1NgmVu-0007v8-Kt < = root@mail-server1.mycompany.com U=root P=local S=424
2010-02-14 23:00:28 1NgmVu-0007v8-Kt => testMail@mycompany.org R=smarthost T=remote_smtp_smarthost H=gmail-smtp-msa.l.google.com [72.14.221.109] X=TLS1.0:RSA_ARCFOUR_MD5:16 DN="C=US,ST=California,L=Mountain View,O=Google Inc,CN=smtp.gmail.com"

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Two words on theory. Password-less connections have to be authenticated at least so strong like the password enabled one, so asymmetric cryptography which enables certificates comes into play.  The clue is to have private and public keys and share your public key with domains which should be able identify you.

So therefore let’s start by generation a needed key-pair.

Generating Keys

It is possible to create key with pass-phrase and without (or empty pass-phrases). I prefer to not use pass phrase because it is asked every-time on later usage of a ssh.
Even there are ways to gives the pass-phrase to ssh command, but it is more work, with no significant security benefits. So i do the following statement and do not enter any pass-phrase (just hit enter on question).

$ ssh-keygen -t rsa

This will create RSA key-pair as following files in ~/.ssh directory:

• id_rsa
• id_rsa.pub

Now public key need to be copied to remote host and has to be added to end of ~/.ssh/authorized_keys file.

Transfer Public keys

The best way to do it is to use ssh-copy-id program which is inside of many linux distributions.

$ ssh-copy-id -i ~/.ssh/id_rsa.pub remote-user@remote-server.org

In that case everything is done automatically and you are ready after that. But if ssh-copy-id is not available, you can copy keys manually e.g. like that.

$ cat ~/.ssh/*.pub | ssh remote-user@remote-server.org 'umask 077; cat >>.ssh/authorized_keys'

Attention! On some linux distrs SSH2 searches for keys in ~/.ssh/authorized_keys2 . Not so in actual Debian (Lenny), but seems to be so in SuSe linux.

Test

Now remote login, scp and sftp can be used without password.
Test it:

# establish connection
$ ssh remote-user@remote-server.org
#or copy files secure and password-less.
$ scp /home/user/some-file remote-user@remote-server.org:/some-path/dir/

More information on SSH related man pages.

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Installing Java SDK

Nowadays  installing Java environment on Debian is an easy task. I used JDK 1.6. Don’t confound JDK with JRE, because bare Java Runtime Environment is not enough for running JBoss. Debian Wiki maintains (hope) a list of available java .deb packages, which are easily can be installed with your preferred way. I prefer aptitude, but apt-get of course works too.

$ aptitude install sun-java6-jdk
#or by good old apt-get.
$ apt-get install sun-java6-jdk

Installation is done after seconds. Now test your java installation with

$ java -version
# Here example result on my configuration:

java version "1.6.0_12"
Java(TM) SE Runtime Environment (build 1.6.0_12-b04)
Java HotSpot(TM) 64-Bit Server VM (build 11.2-b01, mixed mode)

If you get something like this, you’re done and your java should be already in the PATH.

Installing JBoss AS

Now let’s install  JBoss Application Server.

Preparing

Normally you are not willing  to start services (especially when they are accessed from outher machines) with root privileges. Therefore we have to define new user and group which will be used to manage JBoss.  So next line will create new group and new user with this group.

 $ groupadd jboss
 $ useradd -s /bin/bash -d /home/jboss -m -g jboss jboss

This jboss user has no password, so nobody can login with this username. If you consider to  login with jboss user,  password has to be set. Use passwd jboss command for that.

Download, Installation,  filesystem layout

Now  download desired Jboss version. I started with JBoss 5.1.0 GA, which can be download with:

$ cd /tmp # swithch to temp dir
$ wget http://sourceforge.net/projects/jboss/files/JBoss/JBoss-5.1.0.GA/jboss-5.1.0.GA.zip/download

Check also the whole list of verisons if interested. As you may noticed JBoss binaries are packaged with ZIP. So it is comfortable to use unzip tool. Maybe you have to install it first.

But before you extract  downloaded file, we have to decide, where exactly should JBoss files be placed on a  file-system. Unfortunately JBoss is not quite conform to Linux File System Hierarchy Standard per default, so there are many possibilities for a location configuration. Some of you may want to place JBoss  into /opt directory. But I prefer to split the installation a little bit and  want to start by putting  JBoss core files in /usr/local/, where local, unchangeable and read-only files usually placed. E.g. I use  /usr/local/jboss/510 as JBoss 5.1.0 GA root.  So let’s create that location and extract files into it.

mkdir /usr/local/jboss #create new jboss directroy
chown jboss:jboss /usr/local/jboss #now its belongs touser jboss and group jboss
su jboss
mkdir /usr/local/jboss/510
cd /usr/local/jboss/510
unzip /tmp/jboss-5.1.0.GA.zip

At this moment you should have new working JBoss. If you want, test it with

bin/run.sh -b 0.0.0.0

Where -b 0.0.0.0 means that JBoss is listening for every ip address of current machine.

However at this stage the installed Jboss still brakes the  Linux Filesystem Hierarchy Standard, so let’s improve this situation.

After the first start of the server used configuration will have new directories /tmp and /work . The /tmp directory contain the temporarily state of the deployed applications and /work is contains compiled jsp pages of deployed applications. Therefore both directories are of temporal character and  should be on more appropriate place according to Linux standards.

I use only a default JBoss configuration,  which is defined under <jboss_root>/server/default, so I need to do further changes only for this configuration. My decision is to put both directories to /var /tmp/jboss.:

$ mkdir /var/tmp/jboss
$ chown jboss:jboss /var/tmp/jboss/
$ su jboss
$ mkdir /var/tmp/jboss/510
$ mkdir /var/tmp/jboss/510/tmp # creating alternavtive location for tmp
$ mkdir /var/tmp/jboss/510/work # creating alternavtive location for work
$ cd /usr/local/jboss/510/server/default # switch to configuration directory if not allready here.
$ rm -R tmp # delete existing tmp directory (server should not run at this moment)
$ rm -R work # delete existing work directory
$ ln -s /var/tmp/jboss/510/tmp ./tmp # Finaly create symbolic link to new place$
$ ln -s /var/tmp/jboss/510/work ./work # Finaly create symbolic link to new place

repeat the same for /log directory. It is common to have logs at one place in /var/log
create a log directory tree e.g. /var/log/jboss/510/ and let log link to it as was shown for tmp and work directories.

After that your configuration directory should look like:

$ ls -l /usr/local/jboss/510/server/default
drwxr-xr-x  6 jboss jboss 4096 22. Mai 2009  conf
drwxr-xr-x  6 jboss jboss 4096 23. Jan 00:10 data
drwxr-xr-x 15 jboss jboss 4096 22. Mai 2009  deploy
drwxr-xr-x 12 jboss jboss 4096 22. Mai 2009  deployers
drwxr-xr-x  2 jboss jboss 4096 22. Mai 2009  lib
lrwxrwxrwx  1 jboss jboss   19 23. Jan 01:07 log -> /var/log/jboss/510/
lrwxrwxrwx  1 jboss jboss   23 23. Jan 01:13 tmp -> /var/tmp/jboss/510/tmp/
lrwxrwxrwx  1 jboss jboss   24 23. Jan 01:13 work -> /var/tmp/jboss/510/work/

And your logs are of course accessible directly at new location e.g.

tail -1000f /var/log/jboss/510/server.log

Furthermore you should deploy your applications to /srv/jboss/510 to enable this location for automatically scan and deployment,just create a link from /default/deploy/. Call it e.g. applications.:

$ ln -s /srv/jboss/510 ./usr/local/jboss/510/server/default/deploy/applications #

So applications which are placed to /srv/jboss/510 will be automatically deployed on the server.

Start JBoss on boot

First of all you need a life-cycle management script used by init. Jboss already provides some of then.  Let’s use one of Red Hat default script by adopting it a little bit. First of all copy the script to common place (feel free to ad version ti scriptname if you need or like)

$ cp /usr/local/jboss/bin/jboss_init_redhat.sh /etc/init.d/jboss

If you want to access you fresh JBoss also from other IP addresses you need to change
JBOSS_HOST line according to:

JBOSS_BIND_ADDR=${JBOSS_HOST:-"-b 0.0.0.0"}.

0.0.0.0. binds it on all IP addresses. Consider to change also other param this file to mach your personal needs. Now you can automatically create all the symbolic links used by init service.

$ update-rc.d jboss defaults

Now your Jboss will start automatically after reboot…

Additional configuration

• <jboss_root>/bin/run.conf file configures the start parameters of the server. Maybe default limits are not suitable for your applications. So check it.
• Under <jboss_root>/server/default/conf you will find some configuration files of the default server configuration. One of the interesting is of course jboss-lo4j.xml, where you can precisely define logging processing.

Questions & Suggestions

Thank you for reading this. Please feel free to provide any suggestions to the topic of JBoss installation on Linux and specially on Debian. Of course your questions are welcome too!

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RAID 1

Sometimes you need to store data relative save and high available. That is where RAID solutions come in to play. Especially RAID 1 (mirroring) based solutions provide better availability of your data. But don’t forget to use backs anyway

Some days ago i installed RAID 1 on Debian Lenny (amd64 arch) without any troubles for now.
I just was following Jerry’s description which is enough detailed to make no mistakes except maybe one thing.
The Partitions used in the RAID /dev/md0/ should both enable boot flag if you want to boot from RAID.
This is worked for me.

Configuration

My configuration is the same as Jerry’s except partition sizes and chosed LVM. So boot is done form RAID partition /dev/md0. And SWAP is on RAID too, which is controversy solution but it the best one for me, of course availability of a system is primary goal.

So how to check the state of raid after installation. The simplest is to look on /proc file-system with $cat /proc/mdstat. Here is my configuration.

$cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 sda2[0] sdb2[1]
476560128 blocks [2/2] [UU]

md0 : active raid1 sda1[0] sdb1[1]
497856 blocks [2/2] [UU]

unused devices: <none>

Here you see two RAID arrays md0 and md1. Also information about used devices and state are peresent. [UU] stand for “used” for every disc is used in a raid. On diskfailure you wold see something like [U_] and sdb2(F).

Next example utilizes mdadm which is used by kernel in latest kernel versions. My is 2.6.26-2-amd64 (lenny default)
Use of –detail or -D option with a device name gives more information. Here my example.

# mdadm --detail /dev/md1
/dev/md1:
Version : 00.90
Creation Time : Wed Jan  6 00:51:37 2010
Raid Level : raid1
Array Size : 476560128 (454.48 GiB 488.00 GB)
Used Dev Size : 476560128 (454.48 GiB 488.00 GB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent

Update Time : Mon Jan 11 02:18:01 2010
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

UUID : fe3bbbfd:2c6963e7:9785a408:be715448
Events : 0.8

Number   Major   Minor   RaidDevice State
0       8        2        0      active sync   /dev/sda2
1       8       18        1      active sync   /dev/sdb2

GRUB Config

If you wish that your system is able to boot even if one of disks fails completely. You need to write  GRUB loader on every hard disk separately.

Here the example for hd0 ( fist hard disk)

$ grub
grub> root (hd0,0)
Filesystem type is ext2fs, partition type 0xfd
grub> setup (hd0)
setup (hd0)
Checking if "/boot/grub/stage1" exists... no
Checking if "/grub/stage1" exists... yes
Checking if "/grub/stage2" exists... yes
Checking if "/grub/e2fs_stage1_5" exists... yes
Running "embed /grub/e2fs_stage1_5 (hd0)"...  17 sectors are embedded.
succeeded
Running "install /grub/stage1 (hd0) (hd0)1+17 p (hd0,0)/grub/stage2 /grub/menu.lst"... succeeded
Done.

Run the same also for second disk.

grub> root (hd1,0)
...
grub> setup (hd1)

Also your GRUB configuration should enabe loading form the first and alternatively the second disk.

default 0
fallback  1
# is there after installation
title           Debian GNU/Linux, kernel 2.6.18-6-686 Raid (hd0)
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.18-6-686 root=/dev/md0 ro
initrd          /boot/initrd.img-2.6.18-6-686

# manually created
title           Debian GNU/Linux, kernel 2.6.18-6-686 Raid (hd1)
root            (hd1,0)
kernel          /boot/vmlinuz-2.6.18-6-686 root=/dev/md0 ro
initrd          /boot/initrd.img-2.6.18-6-686

The default option declares the first configuration to run on default. fallback option forces grub to load fallback configuration (here hd1)
when the firt one could not start.

You’r done.

Monitoring

Once you run your “high”-available RAID you’re probably very interested to be informed about problems with it.
E.g. on a failure of one (hope only one) HD device.

Yet i know only two most common solutions for monitoring Software RAID. First of it bases on Nagios tool, but is not described here, because not tired yet. The second is to involve mdadm again.

The option –monitor causes mdadm periodically poll a your md arrays and to inform you on every events that occurs. mdadm should never exit process, so it should normally be run in the background.
Here is example of sending a mail on event. Of course sendmail must be configured.

mdadm --monitor --mail=admin@yourcompany.com --scan --delay=1800 -ft

It would run a monitor deamon which scanns all of RAID arrays with delay. The option f starts it as deamon process and t option generates test messages on a startup.

When you want to run mdadm through crone job so use option -1

mdadm --monitor--scan -1

Also this would send your mail or run program which are specified in /etc/mdadm.conf file.
Please see manual of mdadm for more details.

Test Performance

You can test our physical drives with hdparm utility e.g.

hdparm -tT /dev/hda

But hdparm would not correct work on your mdX RAID arrays.

So one of the simplest methods is to try time utility.

time dd if=/dev/md0 of=/dev/null bs=1024k count=1000

This test reads 1 GB data file from you RAID Array but reports to copy only something like “509804544 Bytes (510 MB) in 5,73989 s, 88,8 MB/s” by me. So why only half of the Gigabyte? Just be cause it utilizes two devices, as i think, and indeed it copies 500MB two times parallel = 1 Gig. And this only in the half of time as it needed to red 1 Gigabyte from physical /dev/sda directly.

time dd if=/dev/zero bs=1024k count=1000 of=/home/1Gb.file

This test writes 1 Gb file on RAID partition /home . Therefore you can compare write performance with RAID and non raid partitions but don’t expect any considerable advantages on Mirroring systems

The last one more professional but also complex tools is iozone. It can perform a various of tests,which can’t be explained here detailed.
Please read manual if you really need to test your raid that way. Alternatively you can start iozone in automatic mode, which performs various of tests (relative long-running) and prints on console.

iozone -a

See on Strided Read column which should consider software RAID bonus.

Failure and Recovery

RAID 1 should preserve you from data loose and improve your scalability. So it  is very good idea to has relative good knowledge of what to do on Failure. Best way to get this knowledge is to simulate failure. Take try to remove one disk and put it again into array.

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tar

Tar archives are the most common way of distributing bundles of files under Linux or UNIX. A .tar file is simply a bundle of files packaged with GNU tar program. To extract such files use following:

tar xf somearchive.tar
tar xvf somearchive.tar

• Provide option f if you want to extract content of files. Tar (from tape archive) has long history and was intended to work with tape media, so when you omit f tar tries to work with tape device.
• v- stands for verbose. List all the files by extract process.
• x- Extract command

Before extracting you may be interested in Looking inside of tar. Do it with option “t” :

tar tf archive.tar

For more tar parameters see Man pages.

gzip

Often tar-files are also compressed. One of the most known compressed formats is GNU Zip (gzip).  Tar bundeld and zipped file would  normally  have extension .tar.gz. To extract such files you can use tar with  “z” option, which causes tar to automatically invoke gzip. Modify abow example  and you get able to extract tar.gz  files too.

tar -xzf somearchive.tar.gz

In old tar version the “z” option is may be not available. In that case just use UNIX pipes:

gzip -dc target.tar.gz | tar xf -

Meaning of gzip options

• d – Do decompress!
• c – write to console (So that tar can take it from there )
• t – Tests file integrity
• l – lists archive file information

You will find more on Man pages.

bzip2

Sometimes you can find files ending with .tar.bz2. That are files packaged with bzip (a block-sorting file compressor). Use it like gzip

tar xjvf filename.tar.bz2

Options d,c,t have the same meaning. More on Man pages.

zcat

Some files have .tar.Z endings. They can be extracted by

zcat somearchive.tar.Z | tar xf -

Look in Man pages for more.

Any questions? You are welcome to comment!

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