Known issues for DB2 for Linux, UNIX and Windows on AIX 5.2, 5.3, 6.1, and 7.1

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Abstract

This document describes known AIX® issues and APARs related to DB2® for Linux, UNIX, and Windows. Fixes for the AIX APARs described below can be obtained from Fix Central at
http://www.ibm.com/eserver/support/fixes/fixcentral/main/pseries/aix

Content

This document lists APARs and issues which relate to interaction between DB2 databases and the AIX operating system. It also makes recommendations on AIX technology levels in order to avoid common high impact issues. There might be additional AIX APARs that are unrelated to DB2 activity but can still impact DB2 databases. For example, certain AIX administration activity can lead to corrupted file systems that contain DB2 data. It is recommended that you consult the AIX fix distribution site at the following location to review other AIX APARs which might impact your system:
http://www.ibm.com/eserver/support/fixes/fixcentral/main/pseries/aix

Recent updates:

  • Dec. 6, 2013
    • added recommendations for DB2 Version 10.5
    • updated recommendations to include AIX 6.1 TL09 and AIX 7.1 TL03
  • Mar. 4, 2013
    • added AIX 5.3 APAR IV37084, 6.1 APARs IV30703/IV27680/IV32845/IV33641, 7.1 APARs IV37083/IV30075/IV33155/IV33316
  • Dec. 28, 2012
    • added AIX 5.3 APAR IV32615, 6.1 APARs IV33483/IV32392/IV31959/IV32467, 7.1 APARs IV33484/IV20656/IV32651
    • The newly added APARs supersede AIX 5.1 APAR IV32140(TL12), 6.1 APARs IV25013(TL06)/IV22133 (TL07)/IV29774(TL08)/IV30167(TL09), 7.1 APAR IV29837(TL02). References to the previous APARs has been removed
  • Dec. 12, 2012
    • added AIX 5.3 APAR IV32140, 6.1 APARs IV25013/IV22133/IV29774/IV30167, 7.1 APARs IV20656/IV29837
  • Dec. 6, 2012
    • updated recommendations for DB2 Version 10.1 by removing recommendation to apply IV22132/IV22982/IV22062 (DB2 Version 10.1 is not vulnerable)
  • Nov. 16, 2012
    • updated recommendations to include AIX 6.1 TL08 and AIX 7.1 TL02
  • Sept 7, 2012
    • added AIX 5.3 APAR IV17950, AIX 6.1 APARs IV10811/IV10812/IV08112
    • updated recommendations for DB2 Version 9.7 on AIX 5.3 to avoid TL12 SP5 due to IV17950
    • updated recommendations for DB2 Version 9.7 on AIX 6.1 to avoid TL05 SP7 due to IV10811
    • updated recommendations for DB2 Version 9.7 and Version 10.1 on AIX 6.1 to avoid TL06 SP6 due to IV10812
    • updated recommendations for DB2 Version 9.7 and Version 10.1 on AIX 6.1 to avoid TL07 GA due to IV08112
  • June 25, 2012
    • Added AIX 6.1 APAR IV22982 (TL06 HIPER APAR corresponding to IV22062, IV22132)
    • Updated recommendations for running AIX TL06 on all DB2 releases due to IV22982
  • June 7, 2012
    • Added AIX 6.1 APAR IV18483/IV14297/IV14524 AIX 7.1 APAR IV13121/IV15184
    • Added "Recommendations for running DB2 Version 10.1 on AIX"
  • June 5, 2012
    • Added AIX 6.1 APAR IV22062, 7.1 APAR IV22132, updated recommended levels for running AIX 6.1 TL07 and 7.1 TL01 to include these APARs
  • May 7, 2012
    • Updated recommendations for running DB2 Versions 9.7, 9.5, and 9.1 to include AIX 7.1 TL01 and AIX 6.1 TL07


For further discussion on this topic, visit this developerWorks forum thread:
https://www.ibm.com/developerworks/community/forums/html/topic?id=668182c6-931f-4220-b779-1debaa3620bf



RECOMMENDED MINIMUM AIX TECHNOLOGY LEVELS:

The recommended minimum technology levels are minimum levels. Unless otherwise indicated, higher Technology (TL) or Service Pack (SP) levels are recommended. The prerequisite levels in the standard DB2 product documentation are the minimum levels required for support and do not change after the product becomes generally available; the recommended minimum levels presented in this document deal with issues discovered after the product became generally available. Following these recommendations can result in increased system stability and reliability.

If you are looking for the recommended levels for the IBM® InfoSphere® Balanced Warehouse™ or IBM Smart Analytics System, refer to this document: http://www.ibm.com/support/docview.wss?uid=swg21429594

Information on APARs which are older than any of the current recommended minimum levels in this document can found at :
http://www.ibm.com/support/docview.wss?&uid=swg21224762

Recommendations for running DB2 Universal Database Version 8.2 on AIX can be found at:
http://www.ibm.com/support/docview.wss?&uid=swg21224762

Recommendations for running DB2 Version 10.5 on AIX
AIX version Recommended minimum AIX technology levels
7.1 TL01 SP6
  • DB2 Version 10.5 requires a minimum C++ runtime level of xlC.rte 12.1.0.0 and xlC.aix61.rte.12.1.0.0
  • TL02: no additional APARs are recommended
  • TL03: no additional APARs are recommended
6.1 TL07 SP6
  • DB2 Version 10.5 requires a minimum C++ runtime level of xlC.rte 12.1.0.0 and xlC.aix61.rte.12.1.0.0
  • TL08: no additional APARs are recommended
  • TL09: no additional APARs are recommended


Recommendations for running DB2 Version 10.1 on AIX
AIX version Recommended minimum AIX technology levels
7.1 GA SP3
  • DB2 Version 10.1 requires a C++ runtime level of xlC.rte 11.1.0.1 and xlC.aix61.rte.11.1.0.1
  • TL01: no additional APARs are recommended
  • TL02: no additional APARs are recommended
  • TL03: no additional APARs are recommended
6.1 TL06 SP5
  • DB2 Version 10.1 requires a C++ runtime level of xlC.rte 11.1.0.1 and xlC.aix61.rte 11.1.0.1
  • TL06: Service Pack 6 should be avoided due to AIX APAR IV10812
  • TL07: GA level (SP0) should be avoided due to AIX APAR IV08112
  • TL08: no additional APARs are recommended
  • TL09: no additional APARs are recommended


Recommendations for running DB2 Version 9.7 on AIX
AIX version Recommended minimum AIX technology levels
7.1 GA SP3 (includes APAR IZ90603)
  • DB2 Version 9.7 requires a C++ runtime level of xlC.rte 11.1.0.0 and xlC.aix61.rte.11.1.0.0.
  • TL01: If upgrading to Service Pack 4, AIX APAR IV22132 should be applied
  • TL02: no additional APARs are recommended
  • TL03: no additional APARs are recommended
6.1 TL06 SP5
  • DB2 Version 9.7 requires a C++ runtime level of xlC.rte 9.0.0.8 and xlC.aix61.rte 9.0.0.8.
  • TL03 : A minimum of Service Pack 9 is recommended.
  • TL04 : A minimum of Service Pack 9 is recommended.
  • TL05 : A minimum of Service Pack 5 is recommended.
    • Service Pack 7 should be avoided due to AIX APAR IV10811
  • TL06: If upgrading to Service Pack 8, AIX APAR IV22982 should be applied
  • TL07: If upgrading to Service Pack 4, AIX APAR IV22062 should be applied
  • TL08: no additional APARs are recommended
  • TL09: no additional APARs are recommended
5.3 TL09
  • 64-bit AIX kernel is required.
  • DB2 Version 9.7 requires a C++ runtime level of xlC.rte 9.0.0.8 and xlC.aix50.rte 9.0.0.8.
  • If upgrading to TL10, no additional APARs are recommended
  • If upgrading to TL11, it is recommended to apply Service Pack 5.
  • If upgrading to TL12, it is recommended to apply Service Pack 2.
  • TL12 Service Pack 5 should be avoided due to AIX APAR IV17950

Recommendations for running DB2 Version 9.5 on AIX
AIX version Recommended minimum AIX technology levels
7.1 GA SP3 (includes APAR IZ90603)
  • DB2 Version 9.5 requires a C++ runtime level of xlC.rte 11.1.0.0 and xlC.aix61.rte.11.1.0.0.
  • TL01: If upgrading to Service Pack 4, AIX APAR IV22132 should be applied
  • TL02: no additional APARs are recommended
  • TL03: no additional APARs are recommended
6.1 TL03
  • 64-bit AIX kernel is required.
  • DB2 Version 9.5 requires a C++ runtime level of xlC.rte 9.0.0.1 and xlC.aix61.rte 9.0.0.1.
  • If upgrading to TL04, no additional APARs are recommended
  • If upgrading to TL05, no additional APARs are recommended
  • If upgrading to TL06, it is recommended to apply Service Pack 2 or higher
  • TL06: If upgrading to Service Pack 8, AIX APAR IV22982 should be applied
  • TL07: If upgrading to Service Pack 4, AIX APAR IV22062 should be applied
  • TL08: no additional APARs are recommended
  • TL09: no additional APARs are recommended
5.3 TL08 Service Pack 2
  • 64-bit AIX kernel is required.
  • DB2 Version 9.5 requires a C++ runtime level of xlC.rte 9.0.0.1 and xlC.aix50.rte 9.0.0.1.
  • If upgrading to TL09, no additional APARs are recommended
  • If upgrading to TL10, no additional APARs are recommended
  • If upgrading to TL11, no additional APARs are recommended
  • If upgrading to TL12, no additional APARs are recommended

Recommendations for running DB2 Version 9.1 on AIX
AIX version Recommended minimum AIX technology levels
7.1 GA SP3 (includes APAR IZ90603)
  • DB2 Version 9.1 requires a C++ runtime level of xlC.rte 11.1.0.0 and xlC.aix61.rte.11.1.0.0.
  • TL01: If upgrading to Service Pack 4, AIX APAR IV22132 should be applied
  • TL02: no additional APARs are recommended
6.1 TL01 Service Pack 2
  • 64-bit AIX kernel is required.
  • DB2 Version 9.1 requires a C++ runtime level of xlC.rte 9.0.0.0 and xlC.aix61.rte 9.0.0.0.
  • If upgrading to TL02, no additional APARs are recommended
  • If upgrading to TL03, no additional APARs are recommended
  • If upgrading to TL04, no additional APARs are recommended
  • If upgrading to TL05, no additional APARs are recommended
  • If upgrading to TL06, it is recommended to apply Service Pack 2 or higher
  • TL06: If upgrading to Service Pack 8, AIX APAR IV22982 should be applied
  • TL07: If upgrading to Service Pack 4, AIX APAR IV22062 should be applied
  • TL08: no additional APARs are recommended
5.3 TL08 Service Pack 2
  • 64-bit AIX kernel is required.
  • Prior to Fix Pack 4, DB2 Version 9.1 requires a C++ runtime level of xlC.rte 8.0.0.4 and xlC.aix50.rte 8.0.0.4.
  • DB2 Version 9.1 Fix Pack 4 and later requires a C++ runtime level of xlC.rte 8.0.0.6 and xlC.aix50.rte 8.0.0.6.
  • If upgrading to TL09, no additional APARs are recommended
  • If upgrading to TL10, no additional APARs are recommended
  • If upgrading to TL11, no additional APARs are recommended
  • If upgrading to TL12, no additional APARs are recommended
5.2 TL08 Service Pack 2
  • 64-bit kernel is required.
  • Prior to Fix Pack 4, DB2 Version 9.1 requires a C++ runtime level of xlC.rte 8.0.0.4 and xlC.aix50.rte 8.0.0.4.
  • DB2 Version 9.1 Fix Pack 4 and later requires a C++ runtime level of xlC.rte 8.0.0.6 and xlC.aix50.rte 8.0.0.6.
  • TL09 is not a recommended level due to AIX APAR IY98056.
  • If upgrading to TL10, it is recommended to apply AIX APAR IY98056.


Notes on following tables:
  • The AIX APARs listed in the following tables might not be specific to any one version of DB2 for Linux, UNIX and Windows, which means they might apply to all in-service versions of the product.
  • If they are specific to a DB2 version or needed to support a certain DB2 function, they are marked as such in the comments.
  • The TL / ML column indicates the Technology Level containing the APAR if one exists. "N/A" means that the APAR is not yet available. Check the AIX Fix Distribution site at http://www.ibm.com/eserver/support/fixes/fixcentral/main/pseries/aix to see if an interim fix is available or contact AIX for further information. With the new AIX service strategy, the listed level will include Release, Technology Level, and Service Pack. For example, 5300-04-02 is AIX 5.3, Technology Level 04, Service Pack 2. This is the same as the output from oslevel -s.
  • A "+" indicates that the fix has been made available after the indicated service level was released. It will also be contained in the next service level where applicable.
  • "??" indicates that the APAR is not yet available in a service pack on the stated Technology Level.


A IX 7.1 APARs for DB2 for Linux, UNIX and Windows fixed after GA
APAR# AIX APAR Description TL Comments
IZ84576 APPS USING USER TRACE HOOKS FAIL WHEN TRACE IS ENABLED 7100-00-02 All DB2 releases contain AIX user trace hooks as an aid to diagnosing low-level performance problems. The DB2 product might abend due to this AIX HIPER APAR if any of the following tools are used on systems running on AIX 6100-06-00/01 or AIX 7100-00-00/01
AIX: trace, tprof, perfpmr, filemon
DB2: db2fodc -hang, db2fodc -perf
DB2: db2service.perf1
An interim fix is available for the AIX 7.1 release at ftp://public.dhe.ibm.com/aix/efixes/iz84576.
IZ90603
IZ96071
ISDIGIT CALL REFERENCING A BAD MEMORY ADDRESS 7100-00-03
7100-01-00
This AIX APAR might cause the DB2 instance to crash. This is due to a trap in character checking or manipulation functions such as isdigit(), isspace(), wctomb().
IZ91562
IZ91842
64K KERNEL HEAP CAUSES PAGING WHEN RAM IS OTHERWISE AVAILABLE 7100-00-03
7100-01-00
This HIPER AIX APAR affects systems running DB2 Version 9.1 or later, 64-bit AIX 6.1 or later, and p5+ hardware or higher. Performance degradation occurs due to paging and is accompanied by high CPU usage by the AIX psmd process. Please see the following technote for details :
http://www.ibm.com/support/docview.wss?uid=swg21417752
IV18483
IV15184
TCP RETRANSMIT PROCESSING IS VERY SLOW 7100-01-04
7100-02-00
This HIPER AIX APAR addresses a problem where retransmission of TCP packets occurs only after a 64 second delay. The DB2 database might experience various performance issues due to client-server communication delays, slowdowns in inter-node communication on partitioned database environment systems, and NFS performance degradation. The vulnerable AIX levels are 6.1 TL06 SP7, 6.1 TL07 SP0-3, 7.1 TL01 SP0-3. An interim fix is available as indicated in the AIX APAR documentation.
IV22132
IV24288
APPLICATION CRASHES WHEN CALLING DLCLOSE() 7100-01-05
7100-02-00
This AIX APAR addresses a problem causing private memory corruption on all DB2 versions prior to DB2 Version 10.1. Only systems running AIX 6.1 TL06 SP8, TL07 SP4, or AIX 7.1 TL01 SP4 are vulnerable, with corresponding bos.rte.libc levels of 6.1.6.18, 6.1.7.15 and 7.1.1.15. The common symptoms are a DB2 server hang or crash due to malloc heap corruption, with trap file diagnostics frequently including malloc, initializeXalan, or other functions in operating system libraries. Interim fixes are available from IBM AIX support as follows:
AIX 6.1 TL06 SP8 ftp://public.dhe.ibm.com/aix/efixes/iv22982
AIX 6.1 TL07 SP4 ftp://public.dhe.ibm.com/aix/efixes/iv22062
AIX 7.1 TL01 SP4 ftp://public.dhe.ibm.com/aix/efixes/iv22132
IV33484
IV20656
IV29837
IV32651
TCP CONNECTION MAY HANG - LAST FEW BYTES MAY NOT EVER BE SENT 7100-00-09
7100-01-07
7100-02-01
7100-03-00
This AIX APAR addresses a rare timing problem, where TCP connections exhibiting very low latency might hang, and eventually time out. This is more likely to occur when communication is occurring over virtual Ethernet on the same machine and where large_send is enabled. The DB2 client or server threads might be seen to hang in TCP functions such as tcprecv, but can still be forced (using "force application"). TCP connections can be monitored with "netstat -Aan". If the number of bytes is unchanging over a long period, this APAR might apply.
IV37083
IV30075
IV33155
IV33316
SYSTEM CRASH IN SEMSLEEP() WHEN CREATING/DELETING SEMAPHORES 7100-00-09
7100-01-07
7100-02-02
7100-03-00
This AIX APAR addresses a system crash which might be triggered by db2stop force / stopsap. It has been seen to occur when SAP and the DB2 software are running together on the same LPAR. One possible trigger of high create/delete semaphore activity is a high rate of connection attempts from the local DB2 client applications while db2stop force is in progress.


AIX 6.1 APARs for DB2 for Linux, UNIX and Windows fixed after GA

APAR# AIX APAR Description TL Comments
IZ09600
IZ12763
SOME TEST CASES MENTIONED BELOW ARE FAILING IN DST.P.1 6100-00-02
6100-01-00
After upgrading a system to AIX 5.3 TL07, AIX 5.3 TL07 SP1, AIX 6.1 GA, or AIX 6.1 GA SP1, the system might report incorrect times for a given time zone. This impacts DB2 operations where times are reported in a local time zone, for example db2 values (CURRENT TIMESTAMP). Systems with any of the following AIX fileset levels are vulnerable: bos.rte.libc 5.3.7.0, 5.3.7.1, 6.1.0.0, or 6.1.0.1.
IZ13230
IZ06884
APP MAY CRASH IF LIBNSL.A IS LOADED AND UNLOADED REPEATEDLY 6100-00-03
6100-01-00
In environments where DB2 logs are archived to TSM, the AND DELETE option of the PRUNE HISTORY DB2 command, might trigger multiple calls to TSM, resulting in repeatedly loading/unloading the library libnsl.a. If enough calls are made, (for example, the DB2 database manager makes calls to delete a large number of logs), the DB2 product might crash due to the problem documented in this APAR.

The suggested workaround is to avoid using the AND DELETE option and to delete logs manually through TSM.
IZ10179
MEMORY LEAK WITH GETGRSET ROUTINE WITH NIS SETUP 6100-01-00 Various memory usage issues, out of memory errors, or crashes might be encountered due to this memory leak. Note that one secondary symptom of this problem is a trap in the NIS function yp_all(), which is addressed in AIX APAR IY98802.
IZ17835 PAGING OUT TO PGSPACE OF MEDIUM PAGES 6100-01-00 This problem affects systems running DB2 Version 9.1 or later, 64-bit AIX 5.3 TL05 or later, and p5+ hardware or higher. In addition, the DB2 shared memory requirements must be volatile.

With lru_file_repage=0 (see vmo -a), and numperm > minperm (see vmstat -v), there is an expectation that computational memory will not get paged out when there is a demand for memory. When there are volatile demands for 64K or medium pages, this might not always be the case.

The symptom is that paging space usage might increase over time as different areas of DB2 shared memory are paged out.

Note that as of DB2 Version 9.1, the DB2 database uses medium pages for shared memory on AIX when available. A workaround exists to disable the use of 64K pages by DB2 databases using the command:

db2set DB2_MEDIUM_PAGE_SUPPORT=OFF

DB2 Version 9.5 also uses medium pages for private memory. In this case, the recommended workaround is to disable 64K pages at the AIX level. These steps require a reboot :
vmo -r -o vmm_mpsize_support=0
IZ22211
IZ22571
INCONSISTENT SYSTEM TIME VALUES RELATED TO CHANGES TO AND FROM DAYLIGHT SAVINGS TIME 6100-01-01
6100-02-00
This HIPER APAR supersedes IZ11729/IZ09392/IZ12763, as incorrect timestamps (1 hour off) were observed going to and from Daylight Savings Time.

Systems with any of the following AIX fileset levels are vulnerable: bos.rte.libc 5.3.7.2-4, 5.3.8.0-1, 6.1.1.0.
IZ70670
IZ67388
IZ65501
IZ65970
CORE DUMP AFTER REFERENCING THE ADDR AFTER GETADDRINFO 6100-02-07
6100-03-04
6100-04-02
6100-05-00
This AIX APAR can cause a DB2 instance to crash intermittently with a wide variety of lower-level symptoms due to memory corruption. DB2 systems with databases cataloged with alternate servers using IP addresses are vulnerable. Example output of "LIST DATABASE DIRECTORY":
Alternate server hostname = 9.1.2.3

Vulnerable AIX levels/filesets:
6100-00-10/11 libc 6.1.0.12/13
6100-01-06/07 libc 6.1.1.7/8
6100-02-05/06 libc 6.1.2.6/7
6100-03-02/03 libc 6.1.3.3/4
6100-04-00/01 libc 6.1.4.0

Specifying a hostname as opposed to an IP address avoids the issue.
IZ71987
IZ71850
IZ72031
IZ71191
IZ71603
64K PAGING TAKING PLACE WHEN AVAILABLE SYSTEM RAM EXISTS 6100-01-08
6100-02-07
6100-03-04
6100-04-04
6100-05-00
This problem affects systems running DB2 Version 9 or later, 64-bit AIX TL05 or later, and p5+ hardware or higher.

Please see the following technote for details :
http://www.ibm.com/support/docview.wss?uid=swg21417752
IZ74508
IZ76227
IZ74932
IOCP GETMULTIPLE COMPLETIONSTATUS() NEVER RETURNS 6100-04-06
6100-05-02
6100-06-00
This AIX APAR causes the DB2 product to hang, thus performing asynchronous I/O writes in the function sqloGetMultipleCompletionStatus on AIX 6.1 TL04.

On AIX 5.3 TL11, the symptom will be an AIX system crash. This is a pervasive problem - you are strongly advised to obtain the fix for the APAR if using IOCP with the DB2 product at the vulnerable AIX levels. An interim fix is available.

DB2 Version 9.7 uses IOCP by default. DB2's use of IOCP can be disabled with the following:
db2set DB2_USE_IOCP=OFF

DB2 Version 9.5 does not use IOCP by default, so DB2 Version 9.5 is not vulnerable to this problem unless explicitly enabled. If IOCP has been enabled, disable it by unsetting the registry variable:
db2set DB2_USE_IOCP=

The DB2 database must be recycled for these changes to take effect.

Disabling use of IOCP in the DB2 database might result in a small performance degradation - the amount might not be significant but will vary from system to system.
DB2 releases prior to Version 9.5 do not use IOCP and are not vulnerable.
IZ84087
IZ83815
IZ84055
IZ83856
IZ81170
THREADED APPLICATION MAY CORE DUMP WITH PROTECTION EXCEPTION 6100-02-10
6100-03-07
6100-04-07
6100-05-03
6100-06-00
In specific configurations where a high degree of forking is required, this AIX APAR might cause spurious traps in multithreaded DB2 systems.

Under this scenario, two traps must occur while an instance is active in order to effect a shutdown of the DB2 software. The first will be handled with a successful retry of execution and the DB2 trap file will contain SEGV_ACCERR. The second trap, which might occur much later in time, will not be handled. The instance will crash with limited diagnostics and there will be no DB2 trap file.

Forking from the main db2sysc process rarely occurs in normal DB2 server processing. Environments using the Quest sys-auth authentication plug-in are highly vulnerable, as the plug-in forks a new process for each authentication. It is recommended to apply this AIX APAR for all systems using the Quest plug-in.
IZ84729 APPS USING USER TRACE HOOKS FAIL WHEN TRACE IS ENABLED 6100-06-02 All DB2 releases contain AIX user trace hooks as an aid to diagnosing low-level performance problems. The DB2 software might abend due to this AIX HIPER APAR if any of the following tools are used on systems running on AIX 6100-06-00/01 or AIX 7100-00-00/01
AIX: trace, tprof, or perfpmr, filemon
DB2: db2fodc -hang, db2fodc -perf
DB2: db2service.perf1
An interim fix is available for the AIX 7.1 release at ftp://public.dhe.ibm.com/aix/efixes/iz84576
IZ92561
IZ92783
IZ87037
IZ91967
IZ91738
64K KERNEL HEAP CAUSES PAGING WHEN RAM IS OTHERWISE AVAILABLE 6100-03-09
6100-04-09
6100-05-05
6100-06-04
6100-07-00
This HIPER AIX APAR affects systems running DB2 Version 9.1 or later, 64-bit AIX 6.1 or later, and p5+ hardware or later. Performance degradation occurs due to paging and is accompanied by high CPU usage by the AIX psmd process. See the following technote for details :
http://www.ibm.com/support/docview.wss?uid=swg21417752
IV10811
IV10812
IV08112
POSSIBLE CRASH POSTING AIO/IOCP PACKET 6100-05-08
6100-06-07
6100-07-01
This AIX APAR causes the system to crash under rare timing conditions when an application is using IOCP (I/O Completion Ports). The following AIX levels are vulnerable:
AIX 5.1 TL12 SP5 - bos.iocp.rte 5.3.12.2
AIX 6.1 TL05 SP7 - bos.iocp.rte 6.1.5.2
AIX 6.1 TL06 SP6 - bos.iocp.rte 6.1.6.16
AIX 6.1 TL07 GA - bos.iocp.rte 6.1.7.0

DB2 Version 9.7 and higher use IOCP by default. The DB2 software's use of IOCP can be disabled with the following command:
db2set DB2_USE_IOCP=OFF
DB2 Version 9.5 does not use IOCP by default, so it is not vulnerable to this problem unless explicitly enabled. If IOCP has been enabled, disable by unsetting the registry variable:
db2set DB2_USE_IOCP=
The DB2 database must be recycled for these changes to take effect.

Disabling use of IOCP in the DB2 database might result in a small performance degradation - the amount might not be significant but will vary from system to system.
DB2 releases prior to Version 9.5 do not use IOCP and are not vulnerable.
IV18483
IV14297
IV14524
TCP RETRANSMIT PROCESSING IS VERY SLOW 6100-06-08
6100-07-04
6100-08-00
This HIPER AIX APAR addresses a problem where retransmission of TCP packets occurs only after a 64 second delay. The DB2 database might experience various performance issues due to client-server communication delays, slowdowns in inter-node communication on partitioned database environment systems, and NFS performance degradation. The vulnerable AIX levels are 6.1 TL06 SP7, 6.1 TL07 SP0-3, 7.1 TL01 SP0-3. An interim fix is available as indicated in the AIX APAR documentation.
IV22982
IV22062
IV23254
APPLICATION CRASHES WHEN CALLING DLCLOSE() 6100-06-09
6100-07-05
6100-08-00
This AIX APAR addresses a problem causing private memory corruption on all DB2 versions prior to DB2 Version 10.1. Only systems running AIX 6.1 TL06 SP8, TL07 SP4, or AIX 7.1 TL01 SP4 are vulnerable, with corresponding bos.rte.libc levels of 6.1.6.18, 6.1.7.15 and 7.1.1.15. The common symptoms are a DB2 server hang or crash due to malloc heap corruption, with trap file diagnostics frequently including malloc, initializeXalan, or other functions in operating system libraries. Interim fixes are available from IBM AIX support as follows:
AIX 6.1 TL06 SP8 ftp://public.dhe.ibm.com/aix/efixes/iv22982
AIX 6.1 TL07 SP4 ftp://public.dhe.ibm.com/aix/efixes/iv22062
AIX 7.1 TL01 SP4 ftp://public.dhe.ibm.com/aix/efixes/iv22132
IV33483
IV32392
IV31959
IV32467
TCP CONNECTION MAY HANG - LAST FEW BYTES MAY NOT EVER BE SENT 6100-06-11
6100-07-07
6100-08-02
6100-09-00
This AIX APAR addresses a rare timing problem, where TCP connections exhibiting very low latency might hang, and eventually time out. This is more likely to occur when communication is occurring over virtual Ethernet on the same machine and where large_send is enabled. The DB2 client or server threads might be seen to hang in TCP functions such as tcprecv, but can still be forced (using "force application"). TCP connections can be monitored with "netstat -Aan". If the number of bytes is unchanging over a long period, this APAR might apply.
IV30703
IV27680
IV32845
IV33641
SYSTEM CRASH IN SEMSLEEP() WHEN CREATING/DELETING SEMAPHORES 6100-06-11
6100-07-07
6100-08-02
6100-09-00
This AIX APAR addresses a system crash which might be triggered by db2stop force / stopsap. It has been seen to occur when SAP and the DB2 software are running together on the same LPAR. One possible trigger of high create/delete semaphore activity is a high rate of connection attempts from the local DB2 client applications while db2stop force is in progress.


AIX 5.3 APARs for DB2 for Linux, UNIX and Windows fixed after Technology Level 8
APAR# AIX APAR Description TL Comments
IZ22292
IZ22212
IZ22646
INCONSISTENT SYSTEM TIME VALUES RELATED TO CHANGES TO AND FROM DAYLIGHT SAVINGS TIME 5300-07-04
5300-08-02
5300-09-00
This HIPER APAR supersedes IZ11729/IZ09392/IZ12763, as incorrect timestamps (1 hour off) were observed going to and from Daylight Savings Time. Systems with any of the following AIX fileset levels are vulnerable: bos.rte.libc 5.3.7.2-4, 5.3.8.0-1, 6.1.1.0
IZ69616
IZ66710
IZ66709
IZ65427
IZ65553
CORE DUMP AFTER REFERENCING THE ADDR AFTER GETADDRINFO 5300-08-09
5300-09-06
5300-10-03
5300-11-02
5300-12-00
This AIX APAR can cause a DB2 instance to crash intermittently with a wide variety of lower-level symptoms due to memory corruption. DB2 systems with databases cataloged with alternate servers using IP addresses are vulnerable. Example output of "LIST DATABASE DIRECTORY":
Alternate server hostname = 9.1.2.3

Vulnerable AIX levels/filesets:
5300-07-10 libc 5.3.7.10
5300-08-08 libc 5.3.8.7
5300-09-05 libc 5.3.9.4
5300-10-02 libc 5.3.10.3
5300-11-00/01 libc 5.3.11.0

Specifying a hostname as opposed to an IP address avoids the issue.
IZ67445
IZ73864
IZ73754
IZ73687
IZ71460
64K PAGING TAKING PLACE WHEN AVAILABLE SYSTEM RAM EXISTS 5300-08-10
5300-09-07
5300-10-04
5300-11-04
5300-12-00
This problem affects systems running DB2 Version 9 or later, 64-bit AIX 5.3 TL05 or later, and p5+ hardware or higher. Please see the following technote for details :
http://www.ibm.com/support/docview.wss?uid=swg21417752
IZ74749
IZ76228
IOCP GETMULTIPLE COMPLETIONSTATUS() NEVER RETURNS 5300-11-05
5300-12-02
This AIX APAR causes the DB2 product to hang, thus performing asynchronous I/O writes in the function sqloGetMultipleCompletionStatus on AIX 6.1 TL04. On AIX 5.3 TL11, the symptom will be an AIX system crash.
This is a pervasive problem - you are strongly advised to obtain the fix for the APAR if using IOCP with the DB2 product at the vulnerable AIX levels. An interim fix is available.

DB2 Version 9.7 uses IOCP by default. The DB2 software's use of IOCP can be disabled with the following:

db2set DB2_USE_IOCP=OFF


DB2 Version 9.5 does not use IOCP by default, so DB2 Version 9.5 is not vulnerable to this problem unless explicitly enabled. If IOCP has been enabled, disable it by unsetting the registry variable:

db2set DB2_USE_IOCP=

The DB2 database must be recycled for these changes to take effect.

Disabling use of IOCP in the DB2 database might result in a small performance degradation - the amount might not be significant but will vary from system to system.
DB2 releases prior to Version 9.5 do not use IOCP and are not vulnerable.
IV17950 POSSIBLE CRASH POSTING AIO/IOCP PACKET 5300-12-06 This AIX APAR causes the system to crash under rare timing conditions when an application is using IOCP (I/O Completion Ports). The following AIX levels are vulnerable:
AIX 5.1 TL12 SP5 - bos.iocp.rte 5.3.12.2
AIX 6.1 TL05 SP7 - bos.iocp.rte 6.1.5.2
AIX 6.1 TL06 SP6 - bos.iocp.rte 6.1.6.16
AIX 6.1 TL07 GA - bos.iocp.rte 6.1.7.0

DB2 Version 9.7 and higher use IOCP by default. The DB2 software's use of IOCP can be disabled with the following command:
db2set DB2_USE_IOCP=OFF
DB2 Version 9.5 does not use IOCP by default, so it is not vulnerable to this problem unless explicitly enabled. If IOCP has been enabled, disable by unsetting the registry variable:
db2set DB2_USE_IOCP=
The DB2 database must be recycled for these changes to take effect.

Disabling use of IOCP in the DB2 database might result in a small performance degradation - the amount might not be significant but will vary from system to system.
DB2 releases prior to Version 9.5 do not use IOCP and are not vulnerable.
IV32615 TCP CONNECTION MAY HANG - LAST FEW BYTES MAY NOT EVER BE SENT 5300-12-07 This AIX APAR addresses a rare timing problem, where TCP connections exhibiting very low latency might hang. This is more likely to occur when communication is occurring over virtual Ethernet on the same machine. Disabling large_send might work around the problem in some cases. The DB2 client or server threads might be seen to hang in TCP functions such as tcprecv, but can still be forced (using "force application"). TCP connections can be monitored with "netstat -Aan". If the number of bytes is unchanging over a long period, this APAR might apply.
IV37084 SYSTEM CRASH IN SEMSLEEP() WHEN CREATING/DELETING SEMAPHORES 5300-12-?? This AIX APAR addresses a system crash which might be triggered by db2stop force / stopsap. It has been seen to occur when SAP and the DB2 software are running together on the same LPAR. One possible trigger of high create/delete semaphore activity is a high rate of connection attempts from the local DB2 client applications while db2stop force is in progress.


AIX 5.2 APARs for DB2 for Linux, UNIX and Windows fixed after Technology Level 8, SP2
APAR# AIX APAR Description ML / TL Comments
IY79272 SYSTEM CRASH 5200-09-00 This AIX APAR might result in an AIX system crash when using the DB2 software on the 32-bit AIX kernel. 32-bit DB2 UDB fenced mode processes (db2fmp , db2hmon) use the AIX 32-bit Large Memory Model and are therefore vulnerable to triggering the AIX crash.

Note that the db2hmon runs on DB2 UDB Version 8.2 even when Health Monitor is not enabled. The following AIX levels are vulnerable: 5.2 TL08 SP2 (bos.up/mp/mp64 5.2.0.87).
IY89387 AIX STOPS RESPONDING TO KEEPALIVES 5200-09-03 This problem causes inactive TCP/IP connections from a DB2 UDB on AIX server to be dropped, resulting in various symptoms such as SQL1224N, SQL30081N rc=32, SQL30108N in a DB2 UDB HADR environment. AIX systems with bos.net.tcp.client 5.2.0.95-97 or 5.3.0.50-52 are vulnerable.
IY97129 PASSWDEXPIRED ROUTINE LEAKS MEMORY ON AIX 5.2 FOR FAILURE CASE 5200-10-00 When the SYSADM_GROUP is not defined in the database manager configuration file, DB2 snapshot monitor requests will end up calling the AIX passwdexpired() as a non-root user as part of some authentication checking.
This will trigger the memory leak described in this APAR. It can cause various excessive memory usage symptoms in a DB2 process, including crashes.
If a system is vulnerable to this problem, it is recommended to explicitly set sysadm_group to the group of the instance owner ID or apply this APAR.
IY85298 35 SECOND DELAY IN AUTHENTICATION ON NIS CLIENT 5200-10-00 On systems using NIS authentication, if the ypbind process is restarted, the DB2 software might experience authentication delays due to this problem, which can cause connection slowdowns as well as other secondary effects.
It can be verified on a system that the DB2 performance issues began at the same time as the ypbind process started using the ps command.
IY98056 DB2 COREDUMPS IN ULOAD() ON 5.2.0.99 / 5.3.0.60 5200-10-02 This problem causes the DB2 software to crash from a trap in the AIX uload() routine when loading or unloading libraries.
The following AIX levels are vulnerable: 5.2 TL09/TL10 (bos.up/mp/mp64 5.2.0.95-105) and 5.3 TL06 (bos.mp/mp64 5.3.0.60-61). While the AIX APAR description states that TL05 is also vulnerable, the problem has not been seen in DB2 databases on TL05 kernel levels.
IZ04757 APP MAY CRASH IF LIBNSL.A IS LOADED AND UNLOADED REPEATEDLY 5200-10-05 In environments where DB2 logs are archived to TSM, the AND DELETE option of the PRUNE HISTORY DB2 command, might trigger multiple calls to TSM, resulting in repeatedly loading and unloading the library libnsl.a. If enough calls are made, (for example, the DB2 database makes calls to delete a large number of logs), the database might crash due to the problem documented in this APAR.
The suggested workaround is to avoid using the AND DELETE clause and delete logs manually through TSM.


Known issues for DB2 database products on AIX
Issue Comments
Using EXTSHM with the DB2 software on AIX may cause performance degradation.
Refer to the following technote for details: Using EXTSHM with DB2 on AIX may cause performance degradation
DB2 password checking daemons are vulnerable to various AIX authentication APARs Refer to the following technote: DB2 password checking daemons are vulnerable to various AIX authentication APARs on AIX 5.3 (1242877)
Does the DB2 software change the instance ID's resource limits? Yes. The data limit is set to 491519 (512-byte units) to avoid heap or stack collisions or memory overwrites. The data limit is close to the practical limit for the 32-bit DB2 software on AIX and a reasonable starting point for the 64-bit DB2 software on AIX. The default limit is 128MB. Some users would set this to unlimited to increase the limit, which is ill-advised on 32-bit AIX. The stack limit is set to 32767 (512-byte units) for completeness.
See the following technote: Setting the user data limit for DB2 on AIX (1175377)

The file limit is set to unlimited to avoid unnecessary errors caused due to files being too big in size. The default is 1GB.
The core limit is set to unlimited in order to get good diagnostic data on first failure in a DB2 crash or trap scenario. The default is 1MB, which is insufficient when diagnosing problems involving a trap.
The rss limit is set to unlimited. This is not really necessary, since the limit is ineffective, but it does avoid an additional possibility to consider when the DB2 software is reporting errors due to lack of memory.
Installation of DB2 Version 9 Fix Packs 1 or 2 on an AIX "CSP" service pack fails with "test: 0402-017 Specify a parameter with this command" Refer to the following technote: DB2 Version 9 Fix Pack 2 install fails on AIX 5.3 TL 4 ... (1259943)
File descriptor leak using Vintela Authentication Services (VAS) with AIX 5.3 TL06 A leak of file descriptors allocated by VAS has been observed in systems after upgrading to AIX 5.3 TL06.
Various symptoms are possible including:
  • growing memory usage in DB2 processes.
  • AIX APAR IZ06123 - a vulnerability exposed by the leak which causes an AIX system crash.
  • DB2 APAR IZ04039 - a vulnerability exposed by the leak which causes memory corruption in the DB2 database, resulting in an instance crash.

While the root cause is still under investigation, a defensive fix which avoids the leak is available from Quest at:
https://support.quest.com/SUPPORT/index?page=solution&id=SOL34944
HACMP APAR IZ07575/IZ08353 causes memory leak in DB2 log manager when archiving to TSM If the DB2 database is configured to archive logs to TSM in an HA environment, a memory leak might occur in the DB2 log manager (db2logmgr). This will cause excessive memory usage in the db2logmgr process. Eventually memory might become exhausted in the process, causing archive failures as well as a possible trap or DB2 instance crash.
32-bit DB2 client applications might hang when they are exiting due to xlC APAR IZ09983/IZ12642 When using version 9 of C++ (xlC) runtime, 32-bit DB2 C++ client applications might hang when they are exiting. Other symptoms include hanging or failing migration of 32-bit DB2 instances. Systems with xlC.rte fileset levels 9.0.0.0 - 9.0.0.3 are vulnerable. The problem is resolved in IZ12642, xlC.rte and xlC.aix50/61.rte 9.0.0.4 (December 2007 IBM C++ Runtime Environment Components for AIX).
A sample stack of the hanging program shows :

 pth_spinlock._global_lock_common          
 pth_mutex._mutex_lock                    
 lock__11LibDescLockFv                                
 terminateAndUnload()                                
 dlclose                            
 unload__11OSSHLibraryFv                              
 sqlexPluginUnload__Fib                          
 sqlexAppLibTerm__Fb                            
 sqloAppLibTerm                        
 mod_fini1                            
 modfini                                
 __modfini                                    
 exit  

DB2/TSM environments prior to DB2 Version 9.1 Fix Pack 3 might hang after upgrade to AIX 5.3 TL06 AIX APAR IY87862, fixed in AIX 5.3 TL06, corrects some behavior in the inheritance of Pthreads scheduling attributes. This causes TSM threads running in DB2 backup or archiving processes to run in "process" scope instead of "system" scope. The result is that some inter-process communication within the DB2 database might be sent to the wrong thread in the DB2 process which invoked TSM, and the DB2 product might hang. The DB2 software has implemented a fix to ensure all threads run in system scope. This is available in APAR IZ01069 (DB2 Version 9.1 Fix Pack 3).

A workaround, which is similar to the fix, is to implement the following, which requires recycling the DB2 instance :
  • add export AIXTHREAD_SCOPE=S to the instance ID's .profile
  • add export AIXTHREAD_SCOPE=S to sqllib/userprofile
  • add AIXTHREAD_SCOPE to the DB2 registry variable DB2ENVLIST:
    db2set DB2ENVLIST="AIXTHREAD_SCOPE"
Warnings about "aio0" device not being installed when installing the DB2 software on AIX 6.1 Warnings might be received at the end of installing DB2 Version 9.1 (prior to Fix Pack 4) on AIX 6.1.
These include the following:

ERROR:mkdev: 0514-519 The following device was not found in the customized
        device configuration database:
        name = 'aio0'

These errors can be ignored as AIO is not required to be configured on AIX 6.1 - the DB2 installation is successful and the DB2 software is able to make use of AIO.
Use of unsupported password encryption methods causes hangs and unexpected errors AIX allows additional password encryption options as of AIX 5.3 TL07 and AIX 6.1.
Prior to DB2 Version 9.5 Fix Pack 4, there are restrictions on support for password lengths and encyrption options (see documentation for the appropriate release/fix pack for details).
The DB2 product might hang or return unexpected errors when using an unsupported encryption option/password length combination. Symptoms include :
  • Connect and authentication requests by the DB2 software hang (DB2 APAR IZ18056 resolved in DB2 Version 9.5 Fix Pack 1)
  • db2start hangs (DB2 APAR IZ36615 resolved in DB2 Version 9.5 Fix Pack 4)
  • db2start fails with "SQL10007 Message "-1390" could not be retrieved. Reason code: "3"." (DB2 Versions 8 and 9.1)
Veritas File System may corrupt DB2 SMS temporary files See the following technote: Veritas File System may corrupt DB2 SMS termporary files (1495849)


For further discussion on this topic, visit this developerWorks forum thread:
https://www.ibm.com/developerworks/community/forums/html/topic?id=668182c6-931f-4220-b779-1debaa3620bf

Related information

IBM eServer Fix Central
Known issues for DB2 UDB on AIX (archive)
Fixes by version for DB2 for Linux UNIX and Windows
Installation requirements (Linux)
Known Issues for DB2 on HP-UX
Known Issues for DB2 on Solaris


Cross reference information
Segment Product Component Platform Version Edition
Information Management DB2 Connect Not Applicable AIX 9.7, 9.5, 9.1 All Editions

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Document information


More support for:

DB2 for Linux, UNIX and Windows

Software version:

9.1, 9.5, 9.7, 10.1, 10.5

Operating system(s):

AIX

Software edition:

Advanced Enterprise Server, Enterprise Server, Express, Workgroup Server

Reference #:

1165448

Modified date:

2013-03-04

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