I'd like to see what SIO produces as well.
 
One Q regarding TCP Window size:
 
 c. Use '65340' for Windows 2000 only environments.
 
So if all CIFS clients are Win2k server, Win2k3 server, or NT / XP, then turning this up will have no detrimental effects?  Seems to me the answer is the typical one - it depends.
 
Thanks for any input
 

Hadrian Baron 
 

 

From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Sto Rage©
Sent: Thursday, March 29, 2007 10:59 AM
To: Langdon, Laughlin T. (Lock)
Cc: toasters@mathworks.com
Subject: Re: CIFS overhead with Netapp Filers

Have you tried to use the SIO tool to see what kind of results that produces against both windows server and the filer?
http://now.netapp.com/NOW/download/tools/sio_ntap/download.shtml (needs NOW account)

-G


On 3/29/07, Langdon, Laughlin T. (Lock) <Langdon.Lock@mayo.edu> wrote:
in my previous posts I point out that this is an empty filer.  Not in prod yet.  So I'm the only one doing anything on it

From: Ganjihal, Chetan [mailto:Chetan.Ganjihal@netapp.com]
Sent: Wed 3/28/2007 10:40 PM
To: Shane Garoutte; Langdon, Laughlin T. (Lock)
Cc: Glenn Walker; toasters@mathworks.com
Subject: RE: CIFS overhead with Netapp Filers

I think it would be important to know the state of the system(filer), the values set for different options, system utilization etc.
If there is a perfstat output with stats gathered during the operation(file copy) being carried out, it will help understand the problem.
 
cheers
Chetan
 
From: Shane Garoutte [mailto:sgaroutte@gmail.com ]
Sent: Thursday, March 29, 2007 12:59 AM
To: Langdon, Laughlin T. ((Lock))
Cc: Glenn Walker; toasters@mathworks.com
Subject: Re: CIFS overhead with Netapp Filers

A quick crawl on NOW provided the following:

if CIFS performance is slow after investigating performance issues, modify the filer's CIFS negotiated buffer size.

   1. Verify that hardware or software problems do not exist within the filer, network and client.
   2. Record the CIFS negotiated buffer size by capturing the output of the filer command:
      options cifs.neg_buf_size
   3. Enter the following filer commands:
      a. cifs terminate
      b. options cifs.neg_buf_size 16644
      c. cifs restart
   4. If the buffer size in step 3b does not improve performance, try the following buffer sizes:
      a. Use '17424'.
      Note:
      Starting with Data ONTAP 6.0.X, allow the buffer size to exceed 17424; therefore, upgrade to a release that fixes bug 33396 only if performance does not improve.
      b. Use '33472' for environments mixed with Windows NT and Windows 2000.
      c. Use '65340' for Windows 2000 only environments.
   5. If performance remains slow:
      a. Re-confirm that hardware or software problems do not exist within the filer, network and client.
      b. Restore the original CIFS negotiated buffer size (refer to steps 2 and 3).
      c. During a performance interruption, capture a packet trace between the filer and Windows client.
      d. Send the packet trace to Network Appliance Technical Support for analysis.


On Mar 28, 2007, at 8:33 AM, Langdon, Laughlin T. ((Lock)) wrote:

I'm doing a straight drag and drop using UNC paths with  a single 1.5gig zip file and a 2.2Gig binary File.  If I add more streams (aka start more than one copy on more than one server the filer happily provides more bandwidth)

From Windows server to windows server I get 500 Mbps

From Windows server to a Netapp 6030 Filer running DOT 7.2.1 I get about 250 Mbps

I've tried TCP windows size, Flow Control, LCAP, Static Link Aggregation, Singe port on the filer (no vif), straight crossover cable.

From: Glenn Walker [mailto:ggwalker@mindspring.com]
Sent: Tuesday, March 27, 2007 5:15 PM
To: Langdon, Laughlin T. (Lock); toasters@mathworks.com
Subject: RE: CIFS overhead with Netapp Filers

Typically, you shouldn't see any performance decrease – rather, you should get better performance.

Are you seeing some sort of decrease?

What I can point out:  with some things (Excel\Word to be specific), MS will implement stuff that's not really documented for the file open\discovery which can cause problems, but I doubt that's what you are running into given the speed you are speaking of.  Likewise, using Windows NLB (LB not HA) doesn't always go very well given the fact that it's not the best technology and sometimes can display interop problems with other vendors (not just NetApp).

What exactly are you doing for your test?

Glenn

From: owner-toasters@mathworks.com [ mailto:owner-toasters@mathworks.com] On Behalf Of Langdon, Laughlin T. (Lock)
Sent: Tuesday, March 27, 2007 2:33 PM
To: toasters@mathworks.com
Subject: CIFS overhead with Netapp Filers

I was wondering what the CIFS overhead for a NetApp filer would be. 

Let's say for instance a Windows Server to Windows Server transfer on the same switch, same subnet, GIG copper interconnects, no TOE card, etc gets me up to about 50% utilization (500Mbps). 

Should that same server to a Netapp Filer see a 20-30% degradation in TX/RX speeds because of CIFS overhead?

What should I expect for data rates in this type of scenario?  Are there any tweaks anyone knows of to decrease this gap?

(same results using static link aggregation, and LACP for the VIF)

Thanks

Lock