Changes between Version 25 and Version 26 of FAQ

Timestamp:

May 27, 2009, 8:19:39 AM (15 years ago)

Author:

Herwig Bauernfeind

Comment:

OT: Added solution to 3.2.5 (unix) performance degradation using LAN Requester

FAQ

@@ -113 +113 @@
 ''Note: Samba Server builds older than 2007-02-26 had problems with Extended Attributes (EAs) in general, both with clients connected with IBM LAN Requester and with clients connected with the older Samba 3.0.9 plugins for Netdrive.
 ----
+'''Marcel Müller wrote:'''
+> since I switched my linux server with a 3.0.2x build of samba to debian lenny with samba 3.2.5, the throughput from OS/2 clients using IBM peer dramatically degraded. I get at most 2.5 MB/s when writing from the OS/2 client to the samba server. The CPU load is low CPU at both systems.[[BR]]
+
+Further analysis showed that the OS/2 chooses sometimes Read/Write RAW and sometimes Read/Write MPX at the connection setup. The MPX modes were normally intended to use simultaneous parallel connections over connectionless transports which does not apply to TCPBEUI.[[BR]]
+The issue might be quite old without much noticeable effect, since Samba 3.0.x supported at least Write MPX by default and no windows server will ever accept the MPX modes over TCPBEUI. Samba 3.2 only made the problem to show up.[[BR]]
+
+Most likely there is some kind of issue during the negotiation. Maybe samba returns some wrong error code that made the client to choose the MPX modes, maybe something else.
+However, there seems to be a much easier solution. Since I disabled the MPX modes in the requester configuration, I was no longer able to reproduce the problem. OS/2 now always uses the Read/Write RAW modes, that provide similar performance that the multiplexed mode.
+There should be no really drawback unless you use IPX transport.[[BR]]
+
+
+'''Solution:'''[[BR]]
+'''========='''[[BR]]
+
+Disable the MPX modes in the IBM peer requester configuration:[[BR]]
+
+ - Edit bootdrive:\IBMLAN\IBMLAN.INI
+
+ - Reset bit 14/15 in the wrkheuristics setting:
+{{{
+;                           1         2         3         4
+;                 012345678901234567890123456789012345678901
+; wrkheuristics = 1111111121311111110001011120111221001111100
+;                               ^^  (old)
+  wrkheuristics = 1111111121311100110001011120111221001111100
+;                               ^^  (new)
+}}}
+ - Restart the requester.
+
+Now the client does no longer try to use the multiplexed modes (without success). The RAW mode is used instead.
+
+
+Marcel