Description of problem: heavy paging if VM is migrated to target host with less memory available than VM is using Version-Release number of selected component (if applicable): ovirt 3.4.2 How reproducible: 100% Steps to Reproduce: - cluster defined with 150% memory overcommitment + ksm enabled - administrator wants to move a VM to a selected target host - VM has X GB memory - Target host has less than X GB free memory - Due to overcommitment engine allows to move VM to target host Actual results: - OVirt starts migrationg VM - Target host runs out of memory - paging starts - Host & VMs stall Expected results: - Either a warning should be displayed or migration should be disabled. Additional info: Indepedent from the configured overcommitment/ksm policy OVirt should compare memory of VM to migrate versus free memory on target host. KSM might compress memory afterwards but this is too late for the migration process itself.
Markus, thanks for the detailed report. This is a result of current considerations while doing balancing and migration, and it will be fixed as a part of Bug 1093038. *** This bug has been marked as a duplicate of bug 1093038 ***