[NTLUG:Discuss] Re: why swap? -- welcome to Gigabit Ethernet

[Robert Citek]

On Friday, Sep 10, 2004, at 12:23 US/Central, Bryan J. Smith wrote:

> On Fri, 2004-09-10 at 13:09, Robert Citek wrote:
>> Any suggestions on how to test this?
>
> They sell hardware to do such, but it is very expensive.  A better 
> route
> would be to use an intelligent switch so it would provide RMON
> statistics.  But then the switch would probably be capable of handling
> it on its own versus a cheap GbE switch.
>
> The RX-errors listed in netstat would be a good first start.

On the Intel card
# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:E0:81:25:72:A6
           inet addr:10.4.0.5  Bcast:10.4.0.255  Mask:255.255.255.0
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:831674417 errors:0 dropped:0 overruns:0 frame:0
           TX packets:905118786 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:100
           RX bytes:938708784 (895.2 Mb)  TX bytes:2589135198 (2469.1 Mb)
           Interrupt:19 Base address:0x1000 Memory:f5000000-f5020000

On the Broadcom:
# ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:06:5B:88:66:C7
           inet addr:10.4.0.4  Bcast:10.4.0.255  Mask:255.255.255.0
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:565868899 errors:0 dropped:0 overruns:0 frame:0
           TX packets:929481655 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:100
           RX bytes:1505223444 (1435.4 Mb)  TX bytes:601997308 (574.1 Mb)
           Interrupt:22


> You might also try switching to 9000 byte jumbo frames and see if
> performance improves.  You'll need to setup a dedicated subnet.  You
> could do this with a VLAN if your switch supports it, although be wary
> of your internal layer 3 routing infrastructure (if you have any at
> all).  In all cases, make sure your switch supports larger than 1500
> byte Ethernet frames (nearly fully 802.1Q compliant switches do).

Will have to do that later.  Of course a better way would be to get 
spare hardware, setup, test, optimize, and then migrate.

> So, if you look at the board physically, are there any additional SRAM
> chips?

Can't right now - physically not accessible.

BTW, turned off swap and transfers improved dramatically.  From another 
list on which I posted this question:

   https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=89226

Seems like an issue with the VM in the kernel:

# uname -va
Linux subaru 2.4.20-31.9bigmem #1 SMP Tue Apr 13 17:11:51 EDT 2004 i686 
athlon i386 GNU/Linux

Regards,
- Robert
http://www.cwelug.org