Red Hat Bugzilla – Bug 1294629
Improve loading external VMs speed
Last modified: 2017-02-06 03:03:33 EST
When probing VMs to import from external provider (currently vCenter) each VM take ~5 seconds because we ask libvirt to provide storage information on each VM. We can improve that by not asking for the storage and adding a new verb to vdsm that returns the storage to specific VMs that the user will select to import
After checking more environments its looks like its ~0.5 second per VM. Still suggested fix will speed the loading of VM list.
Due to capacity constrains, postponing for next release. nevertheless this is a valid use case that should be supported.
The are two bottle neck in probing the VMs: 1. getting the xml description (75% of the load) 2. getting the disk size (25% of the load) If we change the load will be reduce from the first dialog ie getting only the name and the status of the VMs but we still need the data when the user pass the VMs to the next dialog. common scenarios: 1. User will select all the VMs we will not save time. 2. User will select some of the VMs we can save some time 3. User will select some of the VMs and the go back to change the the selection - load time can be even worse. I don't think we need to change it for now until we know what are the common user behavior.
I think it's worth it, listing only the names is a significant speedup mainly because you don't have to iterate over each VM(eliminating 100% of comment #3:) Yes, in case of 1. it won't save anything, but in all other cases it would help a lot.
since the required VDSM API change will land in 4.1, postponing to 4.1
The fix for this issue should be included in oVirt 4.1.0 beta 1 released on December 1st. If not included please move back to modified.
Verification build: rhevm-4.1.0-0.3.beta2.el7 qemu-kvm-rhev-2.6.0-28.el7_3.2.x86_64 libvirt-client-2.0.0-10.el7_3.2.x86_64 vdsm-4.19.1-1.el7ev.x86_64 sanlock-3.4.0-1.el7.x86_64 Verification scenario: 1. Use RHEVM 4.1 with cluster and DC 4.1 compatibility: Load VMs from Xen, VMware and KVM. 2. Compare loading time to loading time of 4.0 Cluster and DC compatibility. Results: VMware loading time with 4.1: 1.5 VMware loading time with 4.0: 13.8