[ovirt-devel] high performance VM preset

[Michal Skrivanek]

Hi all,
we plan to work on an improvement in VM definition for high performance workloads which do not require desktop-class devices and generally favor highest possible performance in expense of less flexibility.
We’re thinking of adding a new VM preset in addition to current Desktop and Server in New VM dialog, which would automatically pre-select existing options in the right way, and suggest/warn on suboptimal configuration
All the presets and warning can be changed and ignored. There are few things we already identified as boosting performance and/or minimize the complexity of the VM, so we plan the preset to:
- remove all graphical consoles and set the VM as headless, making it accessible by serial console. 
- disable all USB. 
- disable soundcard. 
- enable I/O Threads, just one for all disks by default.  
- set host cpu passthrough (effectively disabling VM live migration), add I/O Thread pinning in a similar way as the existing CPU pinning.
We plan the following checks and suggest to perform CPU pinning, host topology == guest topology (number of cores per socket and threads per core should match), NUMA topology host and guest match, check and suggest the I/O threads pinning. 
A popup on a VM dialog save seems suitable.

currently identified task and status can be followed on trello card[1]

Please share your thoughts, questions, any kind of feedback…

Thanks,
michal


[1] https://trello.com/c/MHRDD8ZO