VERY HIGH (up to 180%) processor load

Forums Network Management ZeroShell VERY HIGH (up to 180%) processor load

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    Hello everyone.
    I am happily running zeroshell, with great results, but, after setting up OpenVPN, my system is barely holding up. The processor load is sometimes up to 180%, and it is visibly slowing down my internet speed.

    I am sure that it is connected to the fact that I run Host-to LAN Openvpn server on port 80 (it was the only way, since the person that uses it has only port 80 access). I had to change some things for that.

    It is clear, from the picture, that when VPN is not active(between 23:00 and 6:00 AM), the system load is very low.


    using the top command,i get the following results:

    top - 18:40:39 up 2 days, 17:24,  1 user,  load average: 1.75, 1.62, 1.56
    Tasks: 66 total, 2 running, 64 sleeping, 0 stopped, 0 zombie
    Cpu(s): 46.5% user, 51.9% system, 0.0% nice, 1.6% idle, 0.0% IO-wait
    Mem: 247484k total, 187312k used, 60172k free, 31032k buffers
    Swap: 131064k total, 0k used, 131064k free, 40720k cached

    3997 nobody 20 0 1696 648 556 R 47.8 0.3 477:21.73 pppoe
    4698 root 20 0 4168 2152 1336 S 29.9 0.9 442:04.56 vpn
    4 root 15 -5 0 0 0 S 19.3 0.0 163:11.43 ksoftirqd/0
    1641 root 20 0 59656 31m 2652 S 0.7 12.9 0:46.31 named

    ..So, ppoe takes up 47.8%, and vpn 29.9% ..and that’s an average…

    Thanks in advance for the help. Hope you people understood what I wrote here


    If you are running VPN on port 80, because port 80 is commonly crawled for attempts to find public webservers, I would highly recommend and iptables firewall rule only allowing access from the specific IP your VPN client is connecting from.


    I made the firewall change, but there is no difference.
    The load seems heavily connected with VPN traffic. If VPN connection is idle(<1megabyte) , system load is quite low, ~20% , but at a sustained VPN speed of 7 megabytes (~750 kB/S) , the load is 160%.
    Quite strange, taking into consideration that i can have traffic up to 90 Mbit/s on non-vpn interfaces with minimal load.


    See this:

    You could try turning off compression (, but that isn’t an option yet in ZeroShell.

    You might also try changing the openvpn config to use different encryption method (blowfish, 3des, aes)

    Upgrade hardware, or add an encryption/compression offload card.


    I have also noticed extremely large cpu usage after enabling openvpn. I’ll try to disable compression to see if this helps.


    Do we know if Zeroshell can use the crypto acceleration features of the AMD Geode LX yet?

    This is the combo used in the Soekris net5501 box, I would like to run openVPN in the future, but now I have seen this, I’m worried about it chewing up all my CPU.

    There was some talk of a kernel update earlier this year that would allow for this – I think!?



    I don’t know if it does, I’m not familiar with the hardware offloading/acceleration for such.

    I have posted a patch on the other thread on how to disable compression.


    A few hours ago I upgraded to ZS beta 12 and disabled lzo compression on Openvpn. I think the graph speaks for itself.


    I disabled the compression. Not much of a difference, about 30% less.

    Currently i’m on beta 11. I’ll go to beta 12.

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