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):
Steps to Reproduce:
1. Starting point
* Cluster with no overcommit (100%)
* Host with 8G of 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:
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
For a total of ~5G of available memory on the host (non HP)
# egrep 'MemTotal|Hugepagesize|HugePages_Total' /proc/meminfo
MemTotal: 8173012 kB
Hugepagesize: 1048576 kB
Memory used by HugePages is not subtracted from Scheduling Memory Calculation to scheduling non HP VMs.
(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.