Re: Jumbo Frames

2010-11-18 Thread Rob van der Heij
On Thu, Nov 18, 2010 at 7:20 AM, Alan Altmark alan_altm...@us.ibm.com wrote: Also, a guest's ability to use an OSA is limited by the guest's access to the CPU. Very much. In many scenarios that I worked on, disk I/O throughput or CPU was the limiting factor. I still recall one case where the

Re: Jumbo Frames

2010-11-18 Thread Rob van der Heij
On Wed, Nov 17, 2010 at 7:41 PM, Tom Duerbusch duerbus...@stlouiscity.com wrote: If you have a single engine, I wonder if you are hitting the same class of problem that Websphere has on a single engine? I wouldn't know which class that is. Sure Java can absorb a lot of CPU, and the more power

Jumbo Frames

2010-11-17 Thread Karl Kingston
hi Folks.. We have a z10BC and I'm trying to get Jumbo Frames to work. I set the MTU in Linux to 8992. BUT when I transfer, I'm only seeing 20MB/s? Even if it's between 2 servers on the same box and subnet? Did I misconfigure something?

Re: Jumbo Frames

2010-11-17 Thread Karl Kingston
Forgot to mention: z/VM 5.4, SLES10SP2 is the linux flavor From: Karl Kingston karlkings...@ongov.net To: IBMVM@LISTSERV.UARK.EDU Date: 11/17/2010 12:26 PM Subject:Jumbo Frames Sent by:The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU hi Folks.. We have

Re: Jumbo Frames

2010-11-17 Thread Eric Schadow
Karl Check if jumbo frames are enabled on the switch the mainframe is plugged into. I think cisco switches need to be reloaded after changing the system MTU size to jumbo frames. For networking questions I tend to go right to a packet capture of some sort as the packets never lie - well almost

Re: Jumbo Frames

2010-11-17 Thread Karl Kingston
Did that. We even ran a wireshark trace and ended up seeing frame sizes of 1514. From: Eric Schadow escha...@davisvision.com To: IBMVM@LISTSERV.UARK.EDU Date: 11/17/2010 12:40 PM Subject:Re: Jumbo Frames Sent by:The IBM z/VM Operating System IBMVM

Re: Jumbo Frames

2010-11-17 Thread Mark Wheeler
. If Not Excellence, What? If Not Excellence Now, When? Tom Peters, author of The Little BIG Things Date: Wed, 17 Nov 2010 12:26:45 -0500 From: karlkings...@ongov.net Subject: Jumbo Frames To: IBMVM@LISTSERV.UARK.EDU hi Folks.. We have a z10BC and I'm trying to get Jumbo Frames to work. I

Re: Jumbo Frames

2010-11-17 Thread Tom Duerbusch
Check if jumbo frames are enabled on the switch the mainframe is plugged into. I think cisco switches need to be reloaded after changing the system MTU size to jumbo frames. For networking questions I tend to go right to a packet capture of some sort as the packets never lie - well almost never

Re: Jumbo Frames

2010-11-17 Thread Eric Schadow
Karl Can you capture the entire TCP conversation and see the MSS size. What is the other device? Is the device recording the wireshark trace set to record jumbo frames? I have had VLAN information removed by Windows nic drivers when recording packet captures. Eric -Original Message

Re: Jumbo Frames

2010-11-17 Thread Karl Kingston
: Jumbo Frames Sent by:The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU Karl Can you capture the entire TCP conversation and see the MSS size. What is the other device? Is the device recording the wireshark trace set to record jumbo frames? I have had VLAN information removed

Re: Jumbo Frames

2010-11-17 Thread Eric Schadow
Frames This is a multipart message in MIME format. --=_alternative 006CA10D852577DE_= Content-Type: text/plain; charset=US-ASCII MSS size is 8960 From: Eric Schadow escha...@davisvision.com To: IBMVM@LISTSERV.UARK.EDU Date: 11/17/2010 02:04 PM Subject:Re: Jumbo Frames Sent