Re: slow net on new linux vm

[david l goodrich <dlg%dsrw.org@localhost>]

Less than 1 GB free RAM on the dom 0 (4 GB total) adversely
impacts network performance.
  --david


On Fri, Dec 18, 2015 at 12:02:32PM -0600, david l goodrich wrote:
> Hi, all.  Running the following:
> 
>   monolith# uname -a
>   NetBSD monolith.dsrw.org 6.1.5 NetBSD 6.1.5 (XEN3_DOM0) amd64
>   monolith# pkg_info |grep xen
>   xentools45-4.5.1nb7 Userland Tools for Xen 4.5.x
>   xenkernel45-4.5.1nb1 Xen 4.5.x Kernel
>   monolith#
> 
> And I have a strange problem I can't think of how to
> troubleshoot.  When I create a new linux VM, like this:
> 
>   monolith# cat /xen/conf/errol
>   name       = "errol"
> 
>   ramdisk    = "/xen/kernel/Linux/ubuntu/trusty/amd64/initrd.gz"
>   kernel     = "/xen/kernel/Linux/ubuntu/trusty/amd64/vmlinuz"
>   #bootloader = "/usr/pkg/bin/pygrub"
> 
>   memory     = 256
>   vcpus      = 2
>   disk       = [ 'raw:/dev/mapper/small-vm.errol,xvda,w' ]
>   vif        = [ 'bridge=bridge0' ]
>   monolith#
> 
> The network is so slow as to be unusable.  If I am patient
> enough, the installer finishes, but the slow network problem
> follows to the completed VM - SSH sessions are unusable but `xl
> console errol` works about as quickly as one should expect.
> 
> Old VMs that I've migrated in from probably 4.1 or 4.2 running
> Ubuntu Trusty work great, I'm typing this note to you from one of
> them.
> 
> Even stranger - NetBSD domUs don't exhibit this behavior.
> 
> 
> Has anyone  seen this behavior or have any suggestions for
> troubleshooting?
> 
> --david