CPU-usage on idle VM

udo

Distinguished Member
Apr 22, 2009
5,980
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Ahrensburg; Germany
Hi,
I was seach an issue (not pve related) on a productive system. So I created an test system on my pve2-test-cluster. And had the issue that one almost "idle" server use cpu-time on pve2 which don't be at pve1.9.

The VM is an debian squeeze as ldap-server.

For the host, it's looks like an good working VM, but this happens on the VM:
Code:
top - 07:47:36 up 7 days,  9:58,  2 users,  load average: 0.00, 0.00, 0.00
Tasks:  58 total,   1 running,  57 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:    514728k total,   216592k used,   298136k free,    67960k buffers
Swap:   392184k total,        0k used,   392184k free,   117204k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                                          
    1 root      20   0  2032  708  608 S  0.0  0.1   0:03.72 init                                                                                                             
    2 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd                                                                                                         
    3 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/0                                                                                                      
    4 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/0                                                                                                      
    5 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 watchdog/0                                                                                                       
    6 root      20   0     0    0    0 S  0.0  0.0   0:03.46 events/0                                                                                                         
    7 root      20   0     0    0    0 S  0.0  0.0   0:00.00 cpuset                                                                                                           
    8 root      20   0     0    0    0 S  0.0  0.0   0:00.00 khelper                                                                                                          
    9 root      20   0     0    0    0 S  0.0  0.0   0:00.00 netns                                                                                                            
   10 root      20   0     0    0    0 S  0.0  0.0   0:00.00 async/mgr                                                                                                        
   11 root      20   0     0    0    0 S  0.0  0.0   0:00.00 pm
...
also nothing!

But the host is real working:
Code:
top - 07:40:40 up 7 days, 10:18,  1 user,  load average: 0.00, 0.00, 0.00
Tasks: 175 total,   1 running, 174 sleeping,   0 stopped,   0 zombie
Cpu(s):  2.6%us,  6.2%sy,  0.0%ni, 91.2%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   7914044k total,  5639940k used,  2274104k free,   316412k buffers
Swap:  7340024k total,        0k used,  7340024k free,  3482224k cached

    PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                                        
   [B]7497 root      20   0  686m 303m 2856 S   32  3.9   3357:04 kvm[/B]                                                                                                            
   7528 root      20   0 1202m 883m 1860 S    1 11.4   1249:50 kvm                                                                                                            
 355231 root      20   0  189m  37m 5564 S    1  0.5   0:04.99 pvedaemon                                                                                                      
   2901 root      RT   0  205m  69m  42m S    0  0.9   8:49.90 corosync                                                                                                       
 155284 root      20   0  671m 156m 2864 S    0  2.0  12:22.73 kvm                                                                                                            
 355409 root      20   0  190m  37m 5652 S    0  0.5   0:15.20 pvedaemon                                                                                                      
 358405 root      20   0  190m  37m 5632 S    0  0.5   0:00.95 pvedaemon                                                                                                      
...
PID 7497 is the ldap-server.

First I think that this must be IO (disk/network), but there is no IO! The same happens without active NIC inside the client.

My pve-version:
Code:
pveversion -v
pve-manager: 2.0-18 (pve-manager/2.0/16283a5a)
running kernel: 2.6.32-6-pve
proxmox-ve-2.6.32: 2.0-55
pve-kernel-2.6.32-6-pve: 2.6.32-55
lvm2: 2.02.88-2pve1
clvm: 2.02.88-2pve1
corosync-pve: 1.4.1-1
openais-pve: 1.1.4-1
libqb: 0.6.0-1
redhat-cluster-pve: 3.1.8-3
pve-cluster: 1.0-17
qemu-server: 2.0-13
pve-firmware: 1.0-14
libpve-common-perl: 1.0-11
libpve-access-control: 1.0-5
libpve-storage-perl: 2.0-9
vncterm: 1.0-2
vzctl: 3.0.29-3pve8
vzprocps: 2.0.11-2
vzquota: 3.0.12-3
pve-qemu-kvm: 1.0-1
ksm-control-daemon: 1.1-1

The same visualized: cpu_usage.png

Any hints?

Udo
 
Last edited:
Not really. Please test with the next (6.2 based) kernel - will try to release that soon.
Hi,
I found yesterday the "pve-kernel-2.6.32-7-pve: 2.6.32-56" (but not today for an second machine...)

With this kernel it's looks much better (but VM was migrated to second node, because only this node run the new kernel):
kvm-cpu-usage.jpg

Why dissapear this kernel from the repository?

Udo