Changes between Version 25 and Version 26 of FAQ


Ignore:
Timestamp:
May 27, 2009, 10:19:39 AM (10 years ago)
Author:
herwigb
Comment:

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

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  • FAQ

    v25 v26  
    113113''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.
    114114----
     115'''Marcel Müller wrote:'''
     116> 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]]
     117
     118Further 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]]
     119The 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]]
     120
     121Most 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.
     122However, 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.
     123There should be no really drawback unless you use IPX transport.[[BR]]
     124
     125
     126'''Solution:'''[[BR]]
     127'''========='''[[BR]]
     128
     129Disable the MPX modes in the IBM peer requester configuration:[[BR]]
     130
     131 - Edit bootdrive:\IBMLAN\IBMLAN.INI
     132
     133 - Reset bit 14/15 in the wrkheuristics setting:
     134{{{
     135;                           1         2         3         4
     136;                 012345678901234567890123456789012345678901
     137; wrkheuristics = 1111111121311111110001011120111221001111100
     138;                               ^^  (old)
     139  wrkheuristics = 1111111121311100110001011120111221001111100
     140;                               ^^  (new)
     141}}}
     142 - Restart the requester.
     143
     144Now the client does no longer try to use the multiplexed modes (without success). The RAW mode is used instead.
     145
     146
     147Marcel