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"Warning: OS async I/O limit 128 is lower than recovery batch 1024" in Alert log (Doc ID 471846.1)

Last updated on NOVEMBER 12, 2019

Applies to:

Oracle Database - Enterprise Edition - Version 11.1.0.6 and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Linux x86
Linux x86-64
Linux Itanium

*** Checked for relevance on 12-Apr-2016 ***
***Checked for relevance on 21-Jul-2017***

This issue can affect the Oracle server (RDBMS) running on Linux platforms.

(The warning can occur on other platforms but the required action is platform specific)


Symptoms

An asynchronous I/O limit warning of the form:
  "Warning: OS async I/O limit 128 is lower than recovery batch 1024"
may be signaled in the alert log by recovery slave or coordinator processes if the Linux kernel has not been configured sufficiently for async IO operations.

Operations will still continue but IO operations will not be performed asynchronously which may impact recovery performance.

Cause

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In this Document
Symptoms
Cause
Solution
References

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