Challenge:
- postfix/error[dddd]: ... status=deferred (delivery temporarily suspended: connect to mail.server.tld[/var/run/dspam.sock]: Connection refused)
- mails are not delivered

* Restarting web server apache2
apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName

How to get rid of thi annoying message.

MySQL, UTF8 database, UTF8 table, UTF8 field ... but odd characters inside. How to convert "á" to "á" etc...

Ležel mi tu na stole EDIMAX EW-7206APg, který u klienta nefungoval: neudržel spojení ven na internet déle než pár hodin od zapnutí. Dodatečně jsem přišel na to, že nefungovalo ani tlačítko reset. Po reklamaci a výměně za nový kus jsem ho chtěl podrobit otestování v klidu laboratoře místo @field a zjistil takovou malou pozoruhodnost: tento kus hw je prodáván jako "AP", resp. jako "bezdrátový router" za velmi nízkou cenu. Nikde u prodejců ale není jasně patrno, že se nejedná o WiFi router, ale de-facto WiFi switch!

dir_index is a hashed b-tree implementation for ext3, it's riskfree (Fedora has shipped several releases defaulting to it without incident), and adds a bit of performance to your filesystem.

to update an existing partitions:
0) open a terminal or enter cli
1) sudo tune2fs -O dir_index /dev/hdXY (where X indicates device, normally a and Y indicates partition, normally 1)
2a) sudo updatedb
alternatively, unmount and do
2b) sudo e2fsck -D /dev/hdXY

Temporary solution:

1. sudo apt-get install uml-utilities bridge-utils
2. sudo tunctl -t tap1 -u USER_OF_VBOX_ON_HOST
3. sudo brctl addbr br0
4. sudo ifconfig eth0 0.0.0.0 promisc
5. sudo brctl addif br0 eth0
6. sudo dhclient br0
   OR
   sudo ifconfig br0 STATIC.IP.OF.HOST
7. sudo brctl addif br0 tap1
8. sudo ifconfig tap1 up
9. sudo chmod 0666 /dev/net/tun
10. At the VirtualBox startup panel, choose “Host Interface” and add “tap1″ to “Interface Name”.

The changes you make in /etc/resolv.conf will be erased when you reboot your machine. If you want to make this change permanent, you should install resolvconf package from the Universe repository and update the DNS information in the /etc/resolvconf/resolv.conf.d/base file provided by that package.

Problem: Centreon -> Views -> Graphs gives no result (empty tree of groups with no hosts)

Solution (only for Centreon 2.0): assuming you install Centreon
according to this and all paths are set to their defaults. CentStorage
is NOT running.

/etc/init.d/centstorage start

/etc/init.d/centstorage status
  PID TTY          TIME CMD
 7541 pts/2    00:00:00 centstorage

Almost perfect setup - see Centreon Wiki:
http://en.doc.centreon.com/Nagios3_Centreon2_Ubuntu

Notes:
Ubuntu specific adjustments are not needed anymore.

After installation hints:
http://www.evil.cz/clanek/nagios-centreon-how-delete-localhost-host

Problem: I've installed Nagios 3.04, ndo-utils 1.4b7, and centreon 2 rc7. After I exported the settings from centreon to nagios, I see in centreon under monitoring 2 hosts: localhost and centreon-server. Under configuration, hosts, I see only the centreon-server. Also in Nagios I see only centreon-server and not localhost. How can I delete localhost?