Hi, You disabled "Count Threads As Cores" so you need extra steps to identify which cores you can pin. You can check your CPU cores availability using the lscpu command, look: # lscpu | grep -e NUMA -e ^CPU\(s\) CPU(s): 72 NUMA node0 CPU(s): 0-17,36-53 NUMA node1 CPU(s): 18-35,54-71 The previous command lists physical cores and threads. The following command shows you logical cores running on a physical core: # grep -e "processor" -e "physical id" -e "core id" /proc/cpuinfo | grep -E -A1 -B1 "physical id.*0$" | grep -E -B 2 "core id.* 0$" processor : 0 <-- physical core 0 on socket 0 physical id : 0 core id : 0 -- processor : 36 <-- second thread on physical core 0 on socket 0 physical id : 0 core id : 0 I hope it can help you troubleshoot your scenario. Marcos From: parallax <dd432690@gmail.com> Sent: Sunday, July 28, 2024 6:25 AM To: users <users@ovirt.org> Subject: [External] : [ovirt-users] cpu pinning validation failed - virtual cpu does not exist in vm server with two Gold 6346 this message appears when trying pin any cores after 14 core: 16#16_17#17_18#18_19#19_20#20_21#21_22#22 "cpu pinning validation failed - virtual cpu does not exist in vm" "Count Threads As Cores" is disabled pinning cores from 9 to 15 goes well 0#0_1#1_2#2_3#3_4#4_5#5_6#6_7#7_8#8_9#9_10#10_11#11