XCP-NG 8.3 + pfSense: Fresh install but high CPU load???

On the recommendation of a friend, I decided to try XCP-NG directly on an older server MB that I had available. Basic setup is single socket Xeon, a bunch of memory, and a couple of NICs.

Goal: turn this box into a pfSense router… everything I read beforehand seems to indicate the pfSense works well as a VM and it seemed like a cool little side project! Install went well and, other than the steep learning curve, I quickly had the hypervisor setup with pfSense VM running. I followed all the instructions about putting the VM tools onto pfSense and turning off the TX checksum.

Issue: The host server performance seems to show the physical CPU is barely loaded but pfSense (via management interface) is showing 50-60% CPU load! At this point, there is zero real traffic running! Something is not adding up.

A little help from someone more experienced would be appreciated.

Be aware that virtualizing pfsense isn’t a good idea. There is a reason it is called the forbidden router. But if you choose to proceed down this path I’d suggest looking at system stats. Navigate to DiagnosticsSystem Activity and see what is hogging your CPU load.

I am having the same problem. I followed all the steps in terms of disabling TCP offloading in xcp-ng, and I have disabled all the hardware offloading within Pfsense, but getting 60% CPU load of just interrupts inside Pfsense, while the host shows 1-2% CPU activity only.


Interestingly, I also seem to have a significant limitation in terms of traffic - only 400MBps down, but full 920MBps up using speedtest.net on a 1Gb fiber link (my actual router running non-virtualized Pfsense gets 940/940) - cannot figure that one out.

I ran a systat command to see what is going on here. This is what my output is. Something is going on with the CPU’s for sure. I am on XCP-ng 8.2 latest.

    2 users    Load  0.73  0.63  0.50                  Jan  9 20:40:02
   Mem usage:  67%Phy  2%Kmem                           VN PAGER   SWAP PAGER
Mem:      REAL           VIRTUAL                        in   out     in   out
       Tot   Share     Tot    Share     Free   count
Act  2001M  60556K   3279M      99M    1299M   pages
All  2010M  69496K   3418M     198M                       ioflt  Interrupts
Proc:                                                 810 cow    6418 total
  r   p   d    s   w   Csw  Trp  Sys  Int  Sof  Flt   13K zfod        atkbd0 1
             107        5K  14K   6K   3K  574  16K       ozfod       uhci0 23
                                                         %ozfod  1437 cpu0:xen
 0.0%Sys  37.8%Intr  7.7%User  6.3%Nice 48.2%Idle         daefr  1725 cpu1:xen
|    |    |    |    |    |    |    |    |    |    |   13K prcfr     1 cpu0:r
+++++++++++++++++++>>>>---                            15K totfr     5 cpu0:itlb
                                        21 dtbuf          react   588 cpu0:b
Namei     Name-cache   Dir-cache    145812 maxvn          pdwak     6 cpu1:r
   Calls    hits   %    hits   %      2435 numvn      755 pdpgs     5 cpu1:itlb
   10371   10356 100                   504 frevn        1 intrn   366 cpu1:b
                                                     415M wire    112 xen_et0:c0
Disks  ada0                                         1772M act     107 xen_et0:c1
KB/t   1.38                                          434M inact       xenstore0
tps       1                                             0 laund     1 xbd0 2113
MB/s   0.00                                         1299M free      1 xn0 2114
%busy     0                                          263M buf     336 xn0 2115
                                                                  535 xn0 2116
                                                                  164 xn0 2117
                                                                  789 xn1 2118
                                                                  207 xn1 2119
                                                                   10 xn1 2120
                                                                      xn1 2121
                                                                   12 xn2 2124
                                                                   11 xn2 2125

Similar findings here – xcp-ng 8.3 + pfSense virtualized –