Eric Blake wrote:
On 05/18/2015 01:02 PM, Jim Fehlig wrote:
On 05/18/2015 11:35 AM, Emma Anderson wrote:
hi,
I use xl toolstack to manage vms on a Xen machine, and also pass some custom parameters when creating a vm, for example:
xl create vm.cfg ' param="xyz" '
Documentation on create subcommand in the xl man page describes the 'key=value' options as
key=value It is possible to pass key=value pairs on the command line to provide options as if they were written in the configuration file; these override whatever is in the configfile.
I am moving to libvirt for vm management. How I can pass those extra parameters using libvirt?
I'm not aware of similar functionality in libvirt. You would need to customize the domXML before feeding it to 'virsh create'.
Qemu domains have that ability, via an XML namespace that adds <qemu:commandline>: http://libvirt.org/drvqemu.html#qemucommand
but no one has yet implemented that for Xen domains. If you want to add it, the src/qemu code would be the obvious starting point to copy from.
IIUC, Emma is asking about adding/replacing entries in a config template when creating the domain. E.g. a 'template.xl' config file might contain memory=1024 maxmem=1024 vcpus=4 on_poweroff="destroy" on_reboot="restart" on_crash="destroy" localtime=0 builder="linux" extra='ignore_loglevel' vfb=['type=vnc,vncunused=1'] The template can be "customized" when creating the domain by adding new entries or overriding existing ones, using 'xl create's key=value syntax. E.g. xl create template.xl extra='ignore_loglevel 3 splash=silent' name='sales-webserver' uuid='blabla' 'key' must be one of the supported config items in xl.cfg(5). The libvirt equivalent would be something like virsh create template.xml --cmdline 'ignore_loglevel 3 splash=silent' --name sales-webserver --uuid blabla but I don't think that is supported :-). Regards, Jim