Preferences -> Screensaver lets you set the screensaver preferences. If you really want to stop the screensaver then you can kill the daemon ("File" menu).
Is there a special way (like some menu I had to see for it) to disable the Screensaver?
I don't know how I did it, but I choosed one earlier by some button in the menu I think and switched to one minute and it's annoying a little to watch random animations.
Can I switch it off or select one I like a much and turn-off the shuffle (screensaver randomization)?
Preferences -> Screensaver lets you set the screensaver preferences. If you really want to stop the screensaver then you can kill the daemon ("File" menu).
In Knoppix V6.2.0 (CD) I was able to set the screensaver preferences by using the menu entry XScreenSaver Setup in the System Tools menu. In Knoppix V6.2.1 (CD) I used the menu entry Screensaver in the Preferences menu. There is also the possibility to run the command xscreensaver-demo in the terminal.

SFP TO RJ45 TRANSCEIVER SFP MODULE COPPER SFP OPTICAL PORT TO RJ45 ETHERNET PORT
$7.99
NEW Sealed Cisco SFP-10G-LR 10GBASE-LR SFP+ 1310nm 10km *US Shipping*
$24.00
New Sealed Cisco GLC-LH-SMD 1000BASE-LX/LH SFP Transceiver Module *US
$17.00
Dell Intel X710-DA2 5N7Y5 Dual-Port 10GbE SFP+ PCIe 3.0 x8 Network Adapter
$27.50
Genuine Cisco SFP-10G-SR 0-2415-03 10 Gigabit Transceiver
$5.40
HP 560SFP+ 10GB 2-port PCIe NIC Ethernet ADAPTER 669279-001 w/ (2) 10GB SFP+
$16.99
Intel X520-DA2 10Gb 10Gbe 10 Gigabit Network Adapter NIC Dual Port E10G42BTDA
$28.94
Cisco SFP-10G-SR-S 10g Transceivers ( 5 Pack )
$70.00
Cisco Acacia DP04QSDD-E25-840 400G QSFP-DD Coherent DCO Transceiver Module
$699.99
Cisco QSFP-40G-SR-BD Module 10-2945-02 NEW CLAMSHELL
$45.50