To find whether Ubuntu requires a reboot or not, is as simply as checking if a special file exists.
To do so:
file /var/run/reboot-required -------------------------- ls /var/run/reboot-required | grep required
If the file exists, system would require a reboot.
Quick tip.
If you want to generate a random password, you could use /dev/random, but it is more complex than using apg (Automated Password Generator).
So, to install apg on Fedora, run this command:
# yum install apg
Useful parameters:
Some examples:
Just in case you do not know, tail prints the last ten lines of the indicated file. Like this:
tail /var/log/yum.log
Furthermore, if you want to print more lines you can do it with -n parameter:
tail -n 20 /var/log/yum.log
But I think the most interesting parameter for tail is -f. This parameter allows tail to “follow” the file. New data is displayed as the file grows.
Now, using sed we can append to each new line, a bell sound:
tail -f /var/log/yum.log | sed -e $'s/$/\a/'
Notice that ‘$’ escape sequences will only work on bash.
This was tested on Fedora 16.
I know it is strange to set up this type of configuration on an Ubuntu Desktop, but we had to do it for Internet Services class, and it gave problems to me and most of my class.
I am going to use two virtual machines, both running Ubuntu Desktop. First step is installing bind9.
# apt -get install bind9
The test domain will be “etg.local”
Be careful with using underscore on names.
We are going to start by editing /etc/bind/named.conf.local, to define our zone. I am going to define just one zone. You may want to define also a reverse zone.
named.conf.local
Notice that the “type” of this host is master, that is important. We also can see that I used absolute path to the file, because I did not specified any directory on the options.
Allow-transfer, allow-update and also-notify are allowing our slave dns to transfer the zone(s) file(s).
This is my zone file:
Zone file
We must pay attention to thenames to be fully qualified if they include domain name, and both servers must be declared with NS register.
Finally we configure our DNS, this is my configuration file /etc/resolv.conf
/etc/resolv.conf
Here comes the tricky part, at least with Ubuntu Desktop.
First, we configure /etc/resolv.conf to be equally as in master. Search parameter must be “etg.local” and nameserver “127.0.0.1″
Now, we declare our zone, pay attention:
Zone declaration on slave
As you may see, we declared the type of this server as slave, and we set who is its master(s).
Now it should replicate our zone from master server, but it won’t until we do a couple more of steps to avoid errors of writing permission.
We have to edit the file /etc/apparmor.d/usr.sbin.named
Default usr.sbin.named
We have to find the line highlighted in red.
r stands for read, read permission. So we can deduce that it does not have permission to write the zone, that is the because it gives us permission errors.
We change that line to this:
Modified usr.sbin.named
And the last step is giving all permissions to the the bind group in the bind folder:
# chmod -R 775 /etc/bind
Now we restart first the bind server of the master and then the slave with:
# /etc/init.d/bind9 restart
Then if we want to check the log file to see if everything went fine (slave):
# tail -f /var/log/syslog
Syslog
I highlighted some important messages. It tells us that the zone transfer went fine. Now we finally take a look to our recently replicated zone file.
Note: In the next screenshot you will se that the serial is 2. You can transfer with serial, I just added another register (see www) to show you that it really works
Replicated zone
And that’s all, it should work now.
# apt-get install mysql-client-5.1 mysql-client-core-5.1 mysql-common mysql-server-5.1 mysql-server-core-5.1 mysql-admin mysql-gui-tools-common mysql-query-browser
With this packages we install mysql client, mysql server and some administration tools.
Packages to install
Later, we will be asked to set up a root password:
Asking for root password
Be sure to remember that password.
Once it is installed we can run MySQL Administrator to manage our recently installed server.
MySQL Administrator Connection
It’s highly recommended to create other user to work
Creating a new user
With MySQL Administrator you also can manage backups or check server’s health for example.
And finally, with MySQL Query Browser you can que to your server; create new databases, insert values, sql queries, etc.
Creating a new database with Query Browser
This is an easy and fast tip.
We have to set up a cron job:
$ crontab -e
And then we only have to write this line:
@reboot rm -rf ~/.local/share/Trash/files/*
And that’s it, on each reboot, Trash will be emptied. I tested this on Ubuntu and Fedora.
By default, we can’t delete files in Nautilus 3 with delete key, as we did always, because it’s deactivated.
For enable this on Fedora 15, go to terminal and write this down:
$ gsettings set org.gnome.desktop.interface can-change-accels true
Then go to a nautilus window, click on Edit menu and put the mouse over (don’t press, only hover) ”Delete” and press delete key. You will see the new shortcut at the right.
Once you’ve done it, I recommend to turn it off again:
$ gsettings set org.gnome.desktop.interface can-change-accels false
If you use ubuntu you can use dconf-editor. Press ALT+F2 and write dconf-editor and then follow this path: org > gnome > desktop > interface and check can-change-accels.
Then, do the same as in Fedora, but you may have to hit the key twice.
Don’t forget to uncheck the box for preventing changing other shortcuts.