A fix is available
APAR status
Closed as program error.
Error description
A Tivoli Storage Manager client can crash with a segmentation fault during SnapDiff incremental backup operations under specific timing conditions. Customer/L2 Diagnostics: A callstack similar to the following (Linux) example can be extracted from the dump file: #0 raise () #1 abort () #2 psTrapHandler(int) () #3 <signal handler called> #4 InitializeTxnItem () #5 tlBackObj () #7 baSnapDiffCallBack () #8 cacheObject::walkCallback () #9 bTree::WalkTree () #10 bTree::WalkTree () #11 bTree::WalkTree () #12 bTree::WalkTree () #13 bTree::WalkTree () #14 bTree::WalkTree () #15 bTree::WalkTree () #16 cacheObject::dbQuery () #17 SnapdiffDB::SnapdiffDBQuery () #18 baProcessRequest () #19 baRequestHandler () #20 DccTxnProducer::HandleQueue () #21 DccTxnProducer::Run () #22 DccTxnProducer::DoThread () #23 callDoPThread2 () #24 startThread2 () #25 startThread () #26 start_thread () #27 clone () Errors similar to the following may be reported in the dsmerror.log just prior to the crash: 11/19/2015 01:34:53 ANS3402W psGetHostName(): A system call Failed to determine fully qualified hostname failed with code 6201. 11/19/2015 01:34:53 ANS5250E An unexpected error was encountered. TSM function name : nsGetNasVolumeInfo(): TSM function : dmMapNfsVolume() failed to map remote volume for path: </nas-backup/vol/data>. TSM return code : 6201 TSM file : snapcommon.cpp (437) Initial Impact: Medium Tivoli Storage Manager Versions Affected: All supported Tivoli Storage Manager clients. Additional Keywords: TSM SPECTRUM PROTECT SNAPDIFF SNAP DIFF CRASH ABORT ABEND MSGANS3402W MSGANS5250E PSGETHOSTNAME GETHOSTNAME NETAPP
Local fix
Reducing the number of producer threads may change the timing enough (in some environments) to avoid the conditions required to experience this crash. Add the "TESTFLAG MAXPRODUCERS:1" option to your dsm.opt and initiate a new incremental SnapDiff backup to determine if this avoids the crash. Note that this option may induce increased backup times for this client.
Problem summary
**************************************************************** * USERS AFFECTED: * * Tivoli Storage Manager for Client version 6.4 and 7.1 * * running on AIX and Linux x86_64 * **************************************************************** * PROBLEM DESCRIPTION: * * See ERROR DESCRIPTION * **************************************************************** * RECOMMENDATION: * * Apply fixing level when available. This problem is currently * * projected to be fixed in level 7.1.6. * * Note that until these levels are available, this information * * is subject to change at the discretion of IBM. * **************************************************************** *
Problem conclusion
The fix replaced non-reentrant system function calls with appropriate reentrant ones. Also, added the checking for NULL pointers in snapdiff related routines. As a result, the snapdiff operation crash has been fixed.
Temporary fix
Comments
APAR Information
APAR number
IT13098
Reported component name
TSM CLIENT
Reported component ID
5698ISMCL
Reported release
71L
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-01-11
Closed date
2016-02-18
Last modified date
2016-03-15
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
dsmc
Fix information
Fixed component name
TSM CLIENT
Fixed component ID
5698ISMCL
Applicable component levels
R71L PSY
UP
R71A PSY
UP
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSGSG7","label":"Tivoli Storage Manager"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"71L","Line of Business":{"code":"LOB26","label":"Storage"}}]
Document Information
Modified date:
10 January 2022