All, recently we got into a database(10gR2) hang situation and we were forced to abort the instance . This database has few corrupted blocks which shows in v$database_block_corrutpion and occasionally we get ORA-00607: Internal error occurred while making a change to a data block ORA-00600: internal error code, arguments: [kddummy_blkchk], [18], [109812], [6401], [], [], [], [] but this time we observed a cycle of message as shown below coming for 2 hour so we decided to abort the instance . I have a SR opened but so far the support is not very helpful giving any reason. I was wondering if anyone has any idea on this . Doing block recovery for file 18 block 109812 Block recovery from logseq 7907, block 479993 to scn 23018333209 Thu Oct 8 10:05:07 2009 Recovery of Online Redo Log: Thread 1 Group 2 Seq 7907 Reading mem 0 Mem# 0: /mtrx/oradata/pmtrx/onlinelog/o1_mf_2_5azw407p_.log Mem# 1: /mtrx/oradata/pmtrx/onlinelog/o1_mf_2_5azw44op_.log Thu Oct 8 10:05:07 2009 Recovery of Online Redo Log: Thread 1 Group 3 Seq 7908 Reading mem 0 Mem# 0: /mtrx/oradata/pmtrx/onlinelog/o1_mf_3_6azx44op_.log Mem# 1: /mtrx/oradata/pmtrx/onlinelog/o1_mf_3_6azx4fop_.log Block recovery interrupted at rba 7908.155763.340 Doing block recovery for file 18 block 109812 Block recovery from logseq 7907, block 479993 to scn 23018333209 Thu Oct 8 10:05:08 2009 Recovery of Online Redo Log: Thread 1 Group 2 Seq 7907 Reading mem 0 Mem# 0: /mtrx/oradata/pmtrx/onlinelog/o1_mf_2_5azw407p_.log Mem# 1: /mtrx/oradata/pmtrx/onlinelog/o1_mf_2_5azw44op_.log Thu Oct 8 10:05:08 2009 Recovery of Online Redo Log: Thread 1 Group 3 Seq 7908 Reading mem 0 Mem# 0: /mtrx/oradata/pmtrx/onlinelog/o1_mf_3_6azx44op_.log Mem# 1: /mtrx/oradata/pmtrx/onlinelog/o1_mf_3_6azx4fop_.log Block recovery interrupted at rba 7908.155763.340 Doing block recovery for file 18 block 109812 Thanks in advance -Kar