Description of problem: RHEV makes heavy use of thin-provisioned disk. VDSM support for them includes monitoring of their usage, and transparent resizing of them, without the VM noticing. This feature is built on disk usage polling, because there is no other mean to detect the disk usage, thus the need for extension. The polling may be very frequent, and this is among the biggest, if not the single source of load to libvirt. To improve scalability and resource usage in general, we need an event to notify when disk usage exceeds a threshold. This will allow the feature to work with much less system load. The existing polling has to be kept partially as fallback or as recovery option. This bug tracks the implementation of this feature in RHEV. Version-Release number of selected component (if applicable): 4.17.0
tentatively planned for 3.6 depending on support in QEMU and libvirt
libvirt side in progress, https://www.redhat.com/archives/libvir-list/2015-May/msg00580.html this may be a late delivery
As per last update from libvirt developers, support will most likely slip to 7.3, so we cannot implement this.
as per last comment moving to 4.0 due to platform dependency
Moving to 4.1, as platform bug 1181659 is not yet approved for 7.3.
This request has been proposed for two releases. This is invalid flag usage. The ovirt-future release flag has been cleared. If you wish to change the release flag, you must clear one release flag and then set the other release flag to ?.
(eventually) moved to NEW because I can't work on this until we have the libvirt support available.
Moving back to ASSIGNED, as attached patch was abandoned.
design: https://github.com/oVirt/vdsm/blob/master/doc/thin-provisioning.md
implementation: https://gerrit.ovirt.org/#/q/project:vdsm+branch:master+topic:drivemonitor_event
this is now completed and enabled by default
Was tested and verified in performance environment and seen a good improvement : Lab Topology System topology (using bare metal hosts) 3 DC 5 Clusters 235 Hosts Hera : 4 Hosts leopard : 2 Hosts Nested hosts : 229 VMS 3 SD 1020 VMS Hera : 690 VMS leopard : 330 VMS Scenario matrix Delta between the tests Test Step Old New Build 06.12 Delta in HH:MM:SS Delta in percentage VM Stop 0:00:08 0:00:06 -0:00:02 -25.00% VM Start 0:00:36 0:01:00 0:00:24 66.67% Create VM From template 0:01:09 0:01:21 0:00:12 17.39% Nested Host stop 0:00:34 0:00:27 -0:00:07 -20.59% Nested Host start 0:00:50 0:00:30 -0:00:20 -40.00% Create Nested Host from template 0:01:17 0:01:15 -0:00:02 -2.60% Sent maintenance to 10 hosts 0:00:08 0:00:07 -0:00:01 -12.50% Reboot 10 nested hosts 0:05:15 0:05:25 0:00:10 3.17% Reboot 50 nested hosts 0:05:57 0:05:46 -0:00:11 -3.08% Reboot 80 nested hosts 0:10:35 0:10:34 -0:00:01 -0.16% Reboot 100 nested hosts 0:15:09 0:11:40 -0:03:29 -22.99% Engine restart 0:00:47 0:00:55 0:00:08 17.02%
This bugzilla is included in oVirt 4.2.0 release, published on Dec 20th 2017. Since the problem described in this bug report should be resolved in oVirt 4.2.0 release, published on Dec 20th 2017, it has been closed with a resolution of CURRENT RELEASE. If the solution does not work for you, please open a new bug report.