DB2 - Problem description
Problem IT20368 | Status: Closed |
SQLB_BADHDR ERROR DURING SQLB_VERIFY_PAGE CAUSING FODC DUMPS ANDDB MARKED BAD. | |
product: | |
DB2 FOR LUW / DB2FORLUW / B10 - DB2 | |
Problem description: | |
Some partial writes/reads may occur during rebalance/reduce max or lower high water mark operations causing SQLB_BADHDR errors, FODC dumps and bringing down db2. With this defect fix, a new registry variable is being introduced so that when set, it will verify extents in the following manner to prevent any future bad pages and/or dump detailed diagnostic data into db2diag.log and into a binary dump for further root cause analysis: -New registry variable DB2_EM_PAGE_VERIFICATION (db2set DB2_EM_PAGE_VERIFICATION=TRUE) -Extent verification during rebalance operations -Verifies that one full extent is read successfully, it does not verify data consistency of extent's pages -If extent read was not successful, retry read 2 more times -Verbose logging that dumps diagnostic data on failed reads, and states if re-reads were successful -If read fails both re-reads, release latches and wait for 1 minute then retry extent move operation (retry forever) -Extent verification during reclaim storage (i.e. LOWER HIGH WATER MARK, REDUCE MAX) -Verifies that each page of extent has correct checksum pending the page header is not corrupted -If bad page identified, re-read extent up to 2 more times -If all re-reads fail, stop extent movement and return error -Verbose logging that dumps diagnostic data on failed reads, and states if re-reads were successful With this defect fix, there is also an update to an existing DB2 registry: -Updated registry variable DB2_BCKP_PAGE_VERIFICATION (db2set DB2_BCKP_PAGE_VERIFICATION=TRUE) -Extent verification during offline/online backup -Same page verification as extent verification during reclaim storage -Updated retry on failure to re-read extent up to 2 more times | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Db2 11.1 Mod 3 Fix Pack 3 or higher * **************************************************************** | |
Local Fix: | |
No Local Fix The corrupted tables need to be re-created and re-loaded with data. Some data loss is expected. The data from corrupted tables can be extracted via db2dart /DDEL command to be imported into newly created tables. Link to db2dart command for more details: https://www.ibm.com/support/knowledgecenter/SSEPGG_11.1.0/com.ib m.db2.luw.admin.cmd.doc/doc/r0003477.html | |
available fix packs: | |
Db2 Version 11.1 Mod 3 Fix Pack 3 for Linux, UNIX, and Windows | |
Solution | |
First fixed in Db2 11.1 Mod 3 Fix Pack 3 | |
Workaround | |
not known / see Local fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 26.04.2017 19.03.2018 19.03.2018 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |