Re: Networking: Lots of collisions?

[jmitchel%bigjar.com@localhost]

Hi,

NetBSD (and FreeBSD too) seem to have trouble with the default network
adapter presented by VMWare. I'd recommend shutting own the machine and
change the Operating System type to "Other (64-bit)". Then you'll get an
option to install an e1000 adapter. This will show up in NetBSD as wm0
(not pcn0) and works a lot better. On my machine:

PTI:~# netstat -I wm0
Name  Mtu   Network       Address              Ipkts Ierrs    Opkts Oerrs
Colls
wm0   1500  <Link>        00:0c:29:ab:50:b4  7237520     0 14990168     0 
   0

Hope this helps.

Jason M.

> On Oct 8, 2010, at 11:12 PM, Fredrik Pettai wrote:
>> Hi,
>
> Forgot to mention that its NetBSD/i386.
>
> Looking at vmstat, I can see some things that stand out more than others:
>
> # vmstat
>  procs    memory      page                       disks   faults      cpu
>  r b w    avm    fre  flt  re  pi   po   fr   sr f0 c0   in   sy  cs us sy
> id
>  1 0 0 316088 158332  208   1   0    0   13   53  0  0  836 1763 1678 0  4
> 96
>
> one of two processes are occasionally in the run queue and during that
> many page faults surface:
>
> [...]
>  0 0 0 316092 158336    0   0   0    0    0    0  0  0 1538 3006 3144 0  6
> 94
>  2 0 0 316092 158328 1261   0   0    0    0    0  0  0 1576 3039 3032 8  8
> 84
>  0 0 0 316092 158328    0   0   0    0    0    0  0  0 1527 2900 3120 0  3
> 97
>
>> I just installed a netbsd-5-1-RC4 as a dns server, and I see a lot of
>> collisions:
>>
>> pcn0 in       pcn0 out              total in      total out
>> packets  errs  packets  errs colls   packets  errs  packets  errs colls
>> 39428897     0 22000706     0 5500180  39428897     0 22001100     0
>> 5500180
>>    3227     0     1892     0   474      3227     0     1892     0   474
>>    3373     0     2060     0   514      3373     0     2060     0   514
>>    3168     0     1926     0   482      3168     0     1926     0   482
>>
>> Now, since it's running in VMware, one could guess that it's a
>> underlying problem (in VMware or maybe even in the physical
>> infrastructure).
>> But I also have virtualized Linux machines that are quite busy too, and
>> they don't show this kind of networking problem.
>> (They run in the same VMware hardware)
>>
>> Trying to do a tcpdump shows that the netbsd system doesn't handle that
>> very well either:
>>
>> # tcpdump -i pcn0
>> [...]
>> ^C
>> 5 packets captured
>> 2585 packets received by filter
>> 1726 packets dropped by kernel
>>
>> Doing it on the Linux machine works fine:
>>
>> # tcpdump -i eth0
>> [...]
>> ^C
>> 2844 packets captured
>> 2845 packets received by filter
>> 0 packets dropped by kernel
>>
>> To that I might add that the servers doesn't have any typical CPU load
>> etc.
>>
>> # top -o cpu
>> load averages:  0.59,  0.65,  0.65;               up 0+12:32:18
>> 23:05:05
>> 24 processes: 23 sleeping, 1 on CPU
>> CPU states:  0.0% user,  0.0% nice,  2.0% system,  2.0% interrupt, 96.0%
>> idle
>> Memory: 306M Act, 2852K Inact, 6040K Wired, 7980K Exec, 117M File, 155M
>> Free
>> Swap: 256M Total, 256M Free
>>  PID USERNAME PRI NICE   SIZE   RES STATE      TIME   WCPU    CPU
>> COMMAND
>> 3929 user    85    0    94M   91M netio     20:49  2.69%  2.69% [dns
>> process]
>>
>> Anybody else that has seen something similar? (in VMware?)
>> Any hints on what to do to make the networking stack more optimized?
>> It's currently just the defaults.
>>
>> /P
>
>