Description of problem: The engine seems to allow unintended overcommit in case hugepages are used on the host and the scheduler is scheduling non hugepages VMs. Version-Release number of selected component (if applicable): vdsm-4.30.40-1.el7ev.x86_64 ovirt-engine-4.3.8.2-0.4.el7.noarch How reproducible: Always Steps to Reproduce: 1. Starting point * Cluster with no overcommit (100%) * Host with 8G of memory ==> <max_scheduling_memory>7963934720</max_scheduling_memory> 2. Configure 3 hugepages of 1G each, reboot the host: Scheduling memory is still the same, but we now have only 5G of non HP memory: ==> <max_scheduling_memory>7963934720</max_scheduling_memory> 3. User can run non HP VMs with up to 8G total, which can crash the host, as the real free memory is around 5G after HP configuration. For example, I started 2x 3.5G VMs, for a total of 7G of commited memory (non HP) # vdsm-client Host getStats | grep memCommitted "memCommitted": 7000, For a total of ~5G of available memory on the host (non HP) # egrep 'MemTotal|Hugepagesize|HugePages_Total' /proc/meminfo MemTotal: 8173012 kB HugePages_Total: 3 Hugepagesize: 1048576 kB Actual results: Memory used by HugePages is not subtracted from Scheduling Memory Calculation to scheduling non HP VMs. Expected results: Being subtracted?
(In reply to Germano Veit Michel from comment #0) > 3. User can run non HP VMs with up to 8G total, which can crash the host, as > the real free memory is around 5G after HP configuration. and also run a 3G Hugepages VM at the same time...
As this can get confusing... BZ1804037 - Scheduling Memory calculation disregards huge-pages ---> for not considering statically allocated hugepages at kernel cmdline when calculating scheduling memory BZ1804046 - Engine does not reduce scheduling memory when a VM with dynamic hugepages runs ---> for not considering VMs running with dynamic hugepages when calculating scheduling memory
change SLA team to virt, we're not tracking SLA separately anymore
Verifying according to the https://bugzilla.redhat.com/show_bug.cgi?id=1804037#c5 and #c6 since HugePages are subtracted now and no discussion was continued for the UI issue
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Moderate: Red Hat Virtualization security, bug fix, and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2020:3807