ASM file metadata operation wait time processing

Database version: 11.2.0.3.0

System version: CentOS 5.7

A wait event was encountered: ASM file metadata operation

Web-based information that ASM file metadata operation is an internal wait event, there is no solution to the waiting event and the cause of the problem. However, the wait event is found to be related to the KSV master wait event.

KSV Master Wait event information is more, simply for the library is not Exadata is the parameter cell_offload_processing, modified to False, as follows:

According to the above phenomenon and the log embodiment, from the Oracle official Metalink to find information to know that this is a bug [Bug ID 1308282.1]

Here is an explanation of the bug in the official Metalink documentation:

High ' KSV master wait ' and ' ASM File Metadata operation ' Waits in Non-exadata 11g

Symptoms

High waits for ' KSV master wait ' while doing an ASM file metadata operation were reported when a data migration utility WA S running.

This wait is also seen for a drop of a tablespace.

The AWR showed the top events were CPU (> 100%), with ' ASM file metadata operation ' (7%).

Cause

Event ' KSV Master wait ' indicates the process on the RDBMS side was waiting for a reply from a process on the ASM side.

In 11g, the parameter cell_offload_processing are set to TRUE.

Although that was a parameter is isn't applicable for Non-exadata databases, it caused ASM to try to deliver Smart-scan Resul Rsh

The issue is reported in Bugs 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 minutes too K 4 seconds.

Solution

The following solutions is available for Non-exadata databases:

For the quickest solution, use the workaround. The workaround does not negatively impact non-exadata databases.

This parameter are to are 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

Note:at The time this note was written (March), neither 12.1 nor 11.2.0.3 were available.

The quickest solution given in the official documentation is to modify one of the parameter cell_offload_processing in Oracle and modify it to false.

The functions of the cell_offload_processing parameter are described as follows:

cell_offload_processing
Value: true| FALSE
Features: Enable or disable smart Scan and other smart storage features
Modify: You can use ALTER session or alter system to dynamically modify at the session level or at the systems level

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ASM file metadata operation wait time processing