Failure to allocate an OLDS can occur when an OLDS that is no longer being used is still in the RECON. There is a very small performance impact from leaving it in the RECON, since capture will periodically read from it to see if any log records have been written by IMS:
SQDI710E Allocation failed rc=0x04 err=0x1708 info=0x0002 298 dsn=PS.D9F.CSF.DFSOLP09
This message means that a dataset known to the RECON (meaning that it is in the PRIOLD section for the subsystem) doesn't actually exist. However, since it is in the RECON, capture tries to allocate it and fails. While this doesn't hurt anything, the message can be eliminated by removing the dataset from the RECON.
If a new OLDS is added and doesn't remove ones no longer used by IMS they will still be known to DBRC. A RECON listing can be produced by DBRC with the LIST.LOG ALL option. The listing willl include the PRIOLDS (primary record in the OLDS) which will list all the files that have been allocated.
//DBRC EXEC PGM=DSPURX00,REGION=32M,PARM='READONLY'
//SYSPRINT DD SYSOUT=*
//SYSIN DD *
LIST.LOG ALL
/*
//