DB2 - Problembeschreibung
Problem IC65169 | Status: Geschlossen |
DECOMMIT OF "APPLICATION SHARED MEMORY" AS OF SOLARIS 10 UPDATE 4 CAN CAUSE MEMORY CORRUPTION / DB2 INSTANCE TRAP | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 | |
Problembeschreibung: | |
SOLARIS 10 UPDATE 4 includes an enhancement - multiple page size support for pagable shared memory - which impacts DB2. Solaris will choose the largest page size appropriate for pagable shared memory allocations. DB2 takes advantage of this for Automatic Database Shared Memory, but uses a maximum 64K page size (this is documented). This maximum page size is required as DB2 decommits memory in multiples of 64K. This APAR will address the Application Memory area which currently uses the default page size chosen by Solaris. This memory area also grows and shrinks (is decommited) in multiples of 64K. Given the typical sizes of Application Memory shared allocations, Solaris will choose a page size of 4MB. Whenever DB2 decommits a portion of the large page, the entire page may be reused for other purposes on the system. This could result in perceived memory corruption and a DB2 instance crash, since DB2 is still expecting other ranges on the large page to be valid. However, the nature of the decommit operation on Solaris is such that if DB2 references memory on the page before it is reassigned, the memory page returns to it's previous state and the ranges continue to be valid. Given that all of "in-use" Application Memory is continually accessed, it would be extremely rare for the memory page to be reused by the operating system, and this problem has not been seen by customers. The APAR is resolved by changing Application Memory to use a maximum 64K pagesize on Solaris, similar to AUTOMATIC Database Memory. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * DB2 systems running on Solaris * **************************************************************** * PROBLEM DESCRIPTION: * * See error description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 level containing APAR * **************************************************************** | |
Local-Fix: | |
verfügbare FixPacks: | |
DB2 Version 9.5 Fix Pack 6a for Linux, UNIX, and Windows | |
Lösung | |
Problem first fixed in DB2 Version 9.5 Fix Pack 6 | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Bug-Verfolgung | |
Vorgänger : APAR is sysrouted TO one or more of the following: IC65171 Nachfolger : | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 16.12.2009 22.06.2010 22.06.2010 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.5.FP6 | |
Problem behoben lt. FixList in der Version |