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 Bug 11800170 - 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:

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;
Upgrade to 12.1, when available. OR
Apply the 11.2.0.3 patch set OR
Apply one-off Patch 11800170, if available for your RDBMS and Grid Homes

ASM file metadata operation等待事件与KSV master wait相关，表示数据库端等待ASM端的响应，在11g中参数cell_offload_processing被设为true，这个参数并不适用于非exadata数据库，但是导致asm提供智能的扫描结果。

ITPub博客

ASM file metadata operation

CAUSE

SOLUTION

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