Discussion:
OSA Express GbE performance
(too old to reply)
Aria Bamdad
2006-01-18 15:15:57 UTC
Permalink
Hi,

I was wondering if others have seen the problem I am seeing on a OSA Express
Gigabit Ethernet as compared to a regular OSA Express Fast Ethernet.

When testing an FTP put from VM to a local FTP server, it appears that I get
two to three times better performance when I use the OSA-E FE than the GbE.

Both OSAs are connected to the same physical switch. I have looked at
the port statistics on the switch and don't see any errors or anything else
odd. I don't expect to get better performance out of the GbE port with
this test (since the FTP server is on a Fast Ethernet port) but I would
at least expect similar numbers.

Thanks in advance.

Aria.
Adam Thornton
2006-01-18 15:38:03 UTC
Permalink
Post by Aria Bamdad
Hi,
I was wondering if others have seen the problem I am seeing on a OSA Express
Gigabit Ethernet as compared to a regular OSA Express Fast Ethernet.
My first guess would be that your GigE uses jumbo packets and the
switch is having to chop up and reassemble them to feed them to the
smaller size the FE is expecting.

Adam
Aria Bamdad
2006-01-18 16:28:18 UTC
Permalink
Thanks Adam and Marcy for your comments.

I guess for now I will stick with the fast ethernet. I am running zVM 4.3
and moving to 5.2 in a month or so. Level 2 will not want to work with
4.3 so there is no point in trying.

Once I am on 5.2 and if I still see the same problem, I will open a PMR.

Aria
We have seem some lousy FTP performance too. I had a PMR open, but no
time to work on it so it got closed.=20
There is a slowness associated with multiple outbound FTP interfaces and
equalcostmultipath. I did receive new module for that.
But my old 9672 system, with a single OSA FDDI card was much faster than
a new z990 system with 4 OSA GbE interfaces. I don't think it's the GbE
though - z/OS here with same network configuration can get 12,000K -
23,000K per second. They have more engines, but still...=20
Open a PMR - I still think there's something not right. Just wish I had
more time to work on that. Glenn S. in Level 2 will be familiar with my
PMR.
Marcy Cortes
Wells Fargo
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If you are not the addressee or authorized to receive this for the
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-----Original Message-----
Behalf Of Aria Bamdad
Sent: Wednesday, January 18, 2006 7:16 AM
Subject: [VMESA-L] OSA Express GbE performance
Hi,
I was wondering if others have seen the problem I am seeing on a OSA
Express Gigabit Ethernet as compared to a regular OSA Express Fast
Ethernet.
When testing an FTP put from VM to a local FTP server, it appears that I
get two to three times better performance when I use the OSA-E FE than
the GbE.
Both OSAs are connected to the same physical switch. I have looked at
the port statistics on the switch and don't see any errors or anything
else odd. I don't expect to get better performance out of the GbE port
with this test (since the FTP server is on a Fast Ethernet port) but I
would at least expect similar numbers.
Thanks in advance.
Aria.
Smith, Ann (ISD, IT)
2006-01-19 21:54:00 UTC
Permalink
Did your network folks specifically specify Gbe for the port?
If you just let it be negotiated we've found it doesn't work with our switches.
We ask the network folks to specify Gbe.

-----Original Message-----
From: VM/ESA and z/VM Discussions [mailto:VMESA-***@LISTSERV.UARK.EDU]On
Behalf Of Aria Bamdad
Sent: Wednesday, January 18, 2006 11:28 AM
To: VMESA-***@LISTSERV.UARK.EDU
Subject: Re: OSA Express GbE performance


Thanks Adam and Marcy for your comments.

I guess for now I will stick with the fast ethernet. I am running zVM 4.3
and moving to 5.2 in a month or so. Level 2 will not want to work with
4.3 so there is no point in trying.

Once I am on 5.2 and if I still see the same problem, I will open a PMR.

Aria
We have seem some lousy FTP performance too. I had a PMR open, but no
time to work on it so it got closed.=20
There is a slowness associated with multiple outbound FTP interfaces and
equalcostmultipath. I did receive new module for that.
But my old 9672 system, with a single OSA FDDI card was much faster than
a new z990 system with 4 OSA GbE interfaces. I don't think it's the GbE
though - z/OS here with same network configuration can get 12,000K -
23,000K per second. They have more engines, but still...=20
Open a PMR - I still think there's something not right. Just wish I had
more time to work on that. Glenn S. in Level 2 will be familiar with my
PMR.
Marcy Cortes
Wells Fargo
"This message may contain confidential and/or privileged information.
If you are not the addressee or authorized to receive this for the
addressee, you must not use, copy, disclose, or take any action based on
this message or any information herein. If you have received this
message in error, please advise the sender immediately by reply e-mail
and delete this message. Thank you for your cooperation."
-----Original Message-----
Behalf Of Aria Bamdad
Sent: Wednesday, January 18, 2006 7:16 AM
Subject: [VMESA-L] OSA Express GbE performance
Hi,
I was wondering if others have seen the problem I am seeing on a OSA
Express Gigabit Ethernet as compared to a regular OSA Express Fast
Ethernet.
When testing an FTP put from VM to a local FTP server, it appears that I
get two to three times better performance when I use the OSA-E FE than
the GbE.
Both OSAs are connected to the same physical switch. I have looked at
the port statistics on the switch and don't see any errors or anything
else odd. I don't expect to get better performance out of the GbE port
with this test (since the FTP server is on a Fast Ethernet port) but I
would at least expect similar numbers.
Thanks in advance.
Aria.
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Aria Bamdad
2006-01-20 14:23:16 UTC
Permalink
Ann,

I am the network folk!! Yes, I checked the switch and it shows a GbE
connection. Since it's a fiber GbE port on the switch that I am connecting
to, I don't think any other type of connection would be supported on that
port anyway.

Aria.
Did your network folks specifically specify Gbe for the port?=20
If you just let it be negotiated we've found it doesn't work with our switc=
hes.
We ask the network folks to specify Gbe.
-----Original Message-----
Behalf Of Aria Bamdad
Sent: Wednesday, January 18, 2006 11:28 AM
Subject: Re: OSA Express GbE performance
Thanks Adam and Marcy for your comments.
I guess for now I will stick with the fast ethernet. I am running zVM 4.3
and moving to 5.2 in a month or so. Level 2 will not want to work with
4.3 so there is no point in trying.
Once I am on 5.2 and if I still see the same problem, I will open a PMR.
Aria
We have seem some lousy FTP performance too. I had a PMR open, but no
time to work on it so it got closed.=3D20
There is a slowness associated with multiple outbound FTP interfaces and
equalcostmultipath. I did receive new module for that.
But my old 9672 system, with a single OSA FDDI card was much faster than
a new z990 system with 4 OSA GbE interfaces. I don't think it's the GbE
though - z/OS here with same network configuration can get 12,000K -
23,000K per second. They have more engines, but still...=3D20
Open a PMR - I still think there's something not right. Just wish I had
more time to work on that. Glenn S. in Level 2 will be familiar with my
PMR.
Marcy Cortes
Wells Fargo
"This message may contain confidential and/or privileged information.
If you are not the addressee or authorized to receive this for the
addressee, you must not use, copy, disclose, or take any action based on
this message or any information herein. If you have received this
message in error, please advise the sender immediately by reply e-mail
and delete this message. Thank you for your cooperation."
-----Original Message-----
Behalf Of Aria Bamdad
Sent: Wednesday, January 18, 2006 7:16 AM
Subject: [VMESA-L] OSA Express GbE performance
Hi,
I was wondering if others have seen the problem I am seeing on a OSA
Express Gigabit Ethernet as compared to a regular OSA Express Fast
Ethernet.
When testing an FTP put from VM to a local FTP server, it appears that I
get two to three times better performance when I use the OSA-E FE than
the GbE.
Both OSAs are connected to the same physical switch. I have looked at
the port statistics on the switch and don't see any errors or anything
else odd. I don't expect to get better performance out of the GbE port
with this test (since the FTP server is on a Fast Ethernet port) but I
would at least expect similar numbers.
Thanks in advance.
Aria.
*************************************************************************
This communication, including attachments, is
for the exclusive use of addressee and may contain proprietary,
confidential and/or privileged information. If you are not the intended
recipient, any use, copying, disclosure, dissemination or distribution is
strictly prohibited. If you are not the intended recipient, please notify
the sender immediately by return e-mail, delete this communication and
destroy all copies.
*************************************************************************
Aria Bamdad
2006-01-20 14:50:42 UTC
Permalink
Thanks Alan. I have 5.2 brewing.

Aria.
Right. Fiber is GbE only. The copper 1000baseT connections can be
10/100/1000.
All I can suggest is to get to z/VM 5.1 ASAP. Keep your 4.3 numbers for
comparison, and if 5.1 doesn't help (I think we did some performance work
on the QDIO driver in 4.4), then open a PMR and we'll dig into it.
Alan Altmark
z/VM Development
IBM Endicott
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