We have been dealing with IBM and Cybernetics for a few months trying to get the write combination of drivers built to run Oracle RAC. Supposedly everything is fixed, but now my database (just rebuilt) keeps getting corrupt blocks. I don't expect an answer as to our problem, but what is going to be the quickest way to determine the cause of the block corruption? What trace mechanisms should I be activating from Oracle perspective? Block checking and block check sum I assume, any specific RAC trace tools? Wed Nov 14 22:43:05 2007 Read from controlfile member '+DATA/my50rac/control01.ctl' has found a fractured block (blk# 35, seq# 0) Hex dump of (file 0, block 35) in trace file /oracle/product/admin/my50rac/bdump/my50rac1_lmon_729294.trc Corrupt block relative dba: 0x00000023 (file 0, block 35) Fractured block found during control file block read Data in bad block: check value in block header: 0x0 block checksum disabled Wed Nov 14 22:43:05 2007 Wed Nov 14 22:43:05 2007 ORA-00227: corrupt block detected in control file: (block 35, # blocks 1) Wed Nov 14 22:43:05 2007 ORA-00227: corrupt block detected in control file: (block , # blocks ) Wed Nov 14 22:43:05 2007 Wed Nov 14 22:43:07 2007 Wed Nov 14 22:43:08 2007 Wed Nov 14 22:43:10 2007 Wed Nov 14 22:43:13 2007 Thu Nov 15 12:35:10 2007