VirtualBox install Mac Snow Leopard Server

[Pinokkio]

First of all I have VirtualBox installed on an iMac late 2013 running Linux Mint 19.3. Tricia Cinnamon ( dual boot Mojave in separate partition ) .
I prefer to run Virtualbox under Linux . (BTW not even able to make it work under Mojave )
According the EULA I can run this legally on Mac hardware .First I tried to install my Snow Leopard DVD ( no result ==> boot problem )
After reading in the Parallels software instructions , I found out that only the server version could be installed ( legally,and exclusively ) .
I obtained/bought a Snow Leopard Server version , but I am unable to install .I must do something wrong , since for experimenting I could easily install Win XP .
I see this and then it stops .
Debugger called : panic
BSD process name corresponding to curent thread : Unknown
Mac OS version : Not yet set
Kernel version 10.1.1
System model name : iMac14.1 (VirtualBox)
System uptime in nanoseconds : 153703829
I also tried installing High Sierra , no result .
If I uncheck Efi ==> Fatal : No bootable medium found ! System halted .
If I check Efi i fall in Shell>
What can I do ?

[Pinokkio]

Ok I find this via topic " viewtopic.php?f=22&t=85631"
So now after shell> I typed " exit " and finally I am in Boot Maintenance Manager ....
Is this still in the VM or can I mess up my host system ?
There I don' find the 2 options : Normal and recovery boot .
I have : Boot next value (none) and Autoboot Timi out (0)
I must say that I have for optical a .cdr file .

[paulmc]

For your Mac OS X 10.6 'Snow Leopard' Server VM, recall that the Mac host's CPU by default is passed-through to guest VMs. The 2013 iMac's CPU was released after SL, and Apple's SL installer wouldn't like that. To allow older OS VMs to run on newer CPUs, it's usually necessary to 'spoof' the VM's CPU to be one the older OS recognises. For details, please see the advice from other users in the thread '[Solved]OS X Leopard Install gives a Kernel Panic on start-up'.

For your macOS 10.13 'High Sierra' VM, it's good that you're following that cited sticky thread '[HowTo] Install OSX 10.13 in a VM'. However, note that if you're running VirtualBox 6.1.0 or later (with greatly improved support for installing recent macOS versions), it would no longer be necessary to do any special extra steps via the EFI boot menu (after the High Sierra installer reboots the first time) in Step 4 onwards. In addition, please do make sure that you followed a recommended method to create your OS installer ISO disk-image, e.g., see the companion sticky thread '[HowTo] Create OSX ISO from the OSX Install app'. Finally, as former moderator 'socratis' used to urge, avoid applying unnecessary "Hackintosh"-style Extra Data settings to your VM (typically found in online guides for running macOS VBox VMs on non-Apple hardware).