ASM file metadata operation

CAUSE

Event 'KSV master wait' indicates the process on the RDBMS side is waiting for a reply from a process on the ASM side.   In 11g, the parameter cell_offload_processing is set to TRUE.  Although that is a parameter is not applicable for non-Exadata databases, it caused ASM to try to deliver smart-scan results.   The issue was reported in  - ASM IN KSV WAIT AFTER APPLICATION OF 11.2.0.2 GRID PSU.

After applying the workaround for this issue (see Solution below), a drop of a tablespace that used to take 13 minutes took 4 seconds.

SOLUTION

The following solutions are available for non-Exadata databases:

1. For the quickest solution, use the workaround.  The workaround does not negatively impact non-Exadata databases. This parameter is to be set on the database instance.
   
   
   alter system set cell_offload_processing = false;
2. Upgrade to 12.1, when available. OR
3. Apply the 11.2.0.3 patch set  OR
4. Apply one-off , if available for your RDBMS and Grid Homes

ASM file metadata operation等待事件與KSV master wait相關，表示資料庫端等待ASM端的響應，在11g中引數cell_offload_processing被設為true，這個引數並不適用於非exadata資料庫，但是導致asm提供智慧的掃描結果。