I'm trying to understand huge page in oVirt, I'm quite sure to understand it well.
I have an host with 128GiB. I have configured reserved huge page:
cat /proc/cmdline
... hugepagesz=1GB hugepages=120
$ grep -r . /sys/kernel/mm/hugepages
/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_overcommit_hugepages:0
/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages:120
/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages_mempolicy:120
/sys/kernel/mm/hugepages/hugepages-1048576kB/surplus_hugepages:0
/sys/kernel/mm/hugepages/hugepages-1048576kB/resv_hugepages:0
/sys/kernel/mm/hugepages/hugepages-1048576kB/free_hugepages:120
/sys/kernel/mm/hugepages/hugepages-2048kB/nr_overcommit_hugepages:0
/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages:0
/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages_mempolicy:0
/sys/kernel/mm/hugepages/hugepages-2048kB/surplus_hugepages:0
/sys/kernel/mm/hugepages/hugepages-2048kB/resv_hugepages:0
/sys/kernel/mm/hugepages/hugepages-2048kB/free_hugepages:0
I have a big VM running on it:
<custom_properties>
<custom_property>
<name>hugepages</name>
<value>64</value>
</custom_property>
</custom_properties>
<memory>68719476736</memory>, aka 65536 MiB
<memory_policy>
<guaranteed>34359738368</guaranteed>, aka 32768 MiB
<max>68719476736</max>
</memory_policy>
And it keep failing when I want to start it:
/var/log/ovirt-engine/engine.log:2018-11-14 12:56:06,937+01 ERROR [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (default task-66) [13c13a2c-f973-4ba2-b8bd-260e5b35a047] EVENT_ID: USER_FAILED_RUN_VM(54), Failed to run VM XXX due to a failed validation: [Cannot run VM. There is no host that satisfies current scheduling constraints. See below for details:, The host XXX did not satisfy internal filter HugePages because there are not enough free huge pages to run the VM.]
The huge page fs is mounted:
$ findmnt
| |-/dev/hugepages1G hugetlbfs hugetlbfs rw,relatime,pagesize=1G
| `-/dev/hugepages hugetlbfs hugetlbfs rw,relatime
What am I missing ?