What version of the filer are you running?

This is the checklist I give in the cifs performance class I teach for the netapp SE's. This is based on the experience of actual customers in order of decreasing probability.

1. Network Problems. In one of your earlier emails you stated you were sure this did not apply. Since NFS performance is OK, you are probably correct, but I would run netdiag anyway. 2. Virus Scanner. Some of the previous years implementations of virus scanners were not very friendly with file servers. If you are running a virus scanner on the affected clients, then you might want to temporarily disable it to diagnose the problem. 3. Oplock problems. There is a known timing bug in Win95 redirector that the filer triggers. The short version is that the client is not able to immediately receive a response from a file server. The filer has a provision to insert delays in its responses to avoid this problem. Take a look at the cifs stat OpLkBkNoBreakAck to see if this is happening. If you are getting counts on this stat, please contact CS. We can tune the filer for your environment so this will stop happening. 4.Max_mpx too small. Normally I include this in any list. Since this is happening with Win95 clients, this can be eliminated as a source.

If you cannot identify the problem based on this list, then please work with NetApp CS. They can perform some more detailed tests to identify the source of your problem.

mailto: hawleyr@netapp.com US Mail: Network Appliance Inc. Windows Networking Engineering 495 E Java Dr Phone/pager: 408-822-6661 Sunnyvale, CA 94089 http://www.netapp.com

-----Original Message----- From: Alfred Lerch [mailto:alfred_lerch@mentorg.com] Sent: Thursday, September 28, 2000 12:07 AM To: Toasters Subject: Low SMB throughput

Friends,

we are running a F740 in a heterogenous NFS/SMB environment. While we are completely happy on NFS performance SMB performance is not what we would like it to be. But it is only on some Win95 and NT 4.0 where then throughput is low, other Win95 and NT 4.0 systems with the same configuration are fine (as far as you are able to state that two Windows installations are the same). Looking to our 3Com switches shows us that it is not an issue on the ethernet level. I personally guess that it is a protocol issue between the NetApp and Microsoft implementation of CIFS/SMB/NetBIOS over TCP/IP but I'm unable to verify this.

Any ideas where we might start looking ? Has anyone experienced a similar issue ?

regards

alfred