Recovering from an I/O error on the BSDS

When an I/O error occurs on the only copy of the BSDS, you need to recover the BSDS before Db2 can operate normally. If an I/O error occurs on one copy of the BSDS in a dual-BSDS mode environment, you need to recover that copy of the BSDS before the next restart.

Symptoms

The following message is issued: 

DSNJ126I - BSDS ERROR FORCED SINGLE BSDS MODE
The following messages are then issued: 
DSNJ107I - READ ERROR ON BSDS
           DSNAME=... ERROR STATUS=... 
DSNJ108I - WRITE  ERROR ON BSDS
           DSNAME=... ERROR STATUS=...

Causes

A write I/O error occurred on a BSDS.

Environment

If Db2 is in a dual-BSDS mode and one copy of the BSDS is damaged by an I/O error, the BSDS mode changes from dual-BSDS mode to single-BSDS mode. If Db2 is in a single-BSDS mode when the BSDS is damaged by an I/O error, Db2 terminates until the BSDS is recovered.

Resolving the problem

System programmer response:
  1. Use access method services to rename or delete the damaged BSDS and to define a new BSDS with the same name as the failing BSDS. You can find control statements in job DSNTIJIN.
  2. Issue the Db2 command RECOVER BSDS to make a copy of the good BSDS in the newly allocated data set and to reinstate dual-BSDS mode.