Troubleshooting
Problem
Tivoli Storage Manager client establishes a connection with the Tivoli Storage Manager server but hangs during system state backup
Cause
A system state backup may hang when either the client or server are set to use Jumbo frames, but the other is not. For example, given a Tivoli Storage Manager client has Jumbo frames enabled (or 9014 bytes MTU setting) while the Tivoli Storage Manager server has Jumbo frames disabled (or 1500 bytes MTU setting), this configuration will cause the system state backup to hang.
The MTU setting within a client or server's Network Interface Card (NIC) determines the payload size of ethernet frames. When MTU setting is set to 9000+ bytes, this means Jumbo frames are enabled. In order for this option to work both the client and server must have Jumbo frames enabled, meaning MTU setting should be set to 9014 bytes. Otherwise, the default of 1500 bytes should be used for successful system state backups.
Diagnosing The Problem
First enable a service trace in the client options file, dsm.opt using the trace options below:
traceflags service
tracefile <output_filename_and_path>
the service trace will reveal similar to the following:
01/09/2014 11:48:20.896 [006780] [7104] :
..\..\common\com\commtcp.cpp(2034): TcpReadAvailable: error 10054 during
recv.
01/09/2014 11:48:20.896 [006780] [7104] :
..\..\common\com\commtcp.cpp(2099): ANS1005I TCP/IP read error on socket
= 1700, errno = 10054, reason : 'An existing connection was forcibly
closed by the remote host.'.01/09/2014 11:48:20.896 [006780] [7104] :
..\..\common\com\session.cpp(1519): Recv Verb:
01/09/2014 11:48:20.896 [006780] [7104] :
..\..\common\com\session.cpp(1521): ...error-1
01/09/2014 11:48:20.896 [006780] [7104] :
..\..\common\com\session.cpp(1522): sessRecvVerb: Error -50 from call to
'readRtn'.
Indicating that TCP/IP communication has been severed after data is sent to the Tivoli Storage Manager server.
Resolving The Problem
In order to resolve this issue the MTU setting will have to match on both the Tivoli Storage Manager client Network Interface Card and the Tivoli Storage Manager server switch (or Network Interface Card). The default value is usually 1500 bytes or jumbo packets disabled. In virtual environments the vSwitch will also have to match the MTU setting on the Tivoli Storage Manager client and server.
Product Synonym
TSM
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Document Information
Modified date:
17 June 2018
UID
swg21666146