[Libvirt-cim] [PATCH 2 of 3] [TEST] #2 Add VSMS 15_mod_system_settings.py

[Kaitlin Rupert]

Guo Lian Yun wrote:
> 
> +1 from me.
> 
> I have a question of ModifySystemSettings() and ModifyResourceSettings().
> ModifySystemSettings() method modify the attributes of VSSD, and 
> ModifyResourceSettings()
> intends to modify RASD properties, right? 

The VSSD and RASD instances are just a way of representing the 
properties of the guest.  So these functions really aren't modifying the 
VSSD or RASD instances themselves.

> I have to pass both RASD and 
> VSSD instances to
> DefineSystem() when I try to define a vs. Would you please explain more 
> about VSSD and RASD instance
> for me?

The RASD describes the guest resources.  When you define a system, you 
pass a RASD for each resource you want the guest to have.  If you want 
it to have a disk, you pass in a DiskRASD.  Same thing for proc, mem, 
network, etc.

The RASD is then used by the DefineSystem() call to determine what 
virtual resources to add to the guest. In the case of disk, the DiskRASD 
tells us the path to the disk we're adding.

ModifyResourceSettings() works in a similar way.  If a guest has a disk 
with path /boot/myimage and we want to change it to /boot/not_myimage, 
we set the Address of the DiskRASD to "/boot/not_myimage" and pass that 
DiskRASD to ModifyResourceSettings().

The VSSD is a similar concept, except that it describes the properties 
of the guest itself.  So, we set the VirtualSystemIdentifier attribute 
of the VSSD to give the guest a name. This is passed to the 
DefineSystem() call, so the provider knows what kinds of settings the 
guest should have.

ModifySystemSettings() is used to modify the guest's settings.

-- 
Kaitlin Rupert
IBM Linux Technology Center
kaitlin at linux.vnet.ibm.com