AEM_log Level 0 to level 3 meaning

The log levels are as follows:

0	Fatal error	The action has failed, and the installer cannot proceed.
1	Error	The action has failed. The installation proceeds, but a part of AEM WCM was not installed correctly and will not work.
2	Warning	The action has succeeded but encountered problems. AEM WCM may or may not work correctly.
3	Information	The action has succeeded.

AEM_Log files Basics

Various log files are held on the file server where you installed AEM:

• <cq-installation-dir>/crx-quickstart/logs
  • access.log
    All access requests to AEM WCM and the repository are registered here.
  • audit.log
    Moderation actions are registered here.
  • error.log
    Error messages (of varying levels of severity) are registered here.
  • ImageServer--yyyy>--
    .log
    
    This log is only used if dynamic media is enabled. It provides statistics and analytical information used for analyzing behavior of the internal ImageServer process. 
  • request.log
    Each access request is registered here together with the response.
  • s7access---
    .log
    
    This log is only used if dynamic media is enabled. The s7access log records each request made to Dynamic Media through /is/image and /is/content.
  • stderr.log
    Holds error messages, again of varying levels of severity, generated during startup. By default the log level is set to Warning (WARN)
  • stdout.log
    Holds logging messages indicating events during startup.
  • upgrade.log
    Provides a log of all upgrade operations that runs from the com.day.compat.codeupgrade and com.adobe.cq.upgradesexecutor packages.
• <cq-installation-dir>/crx-quickstart/repository
• revision.log
  Revision journaling information.

Note:

The ImageServer and s7access logs are not included in the Download Full package that is generated from the system/console/status-Bundlelist page. For support purposes, if you have Dynamic Media issues, please also append the ImageServer and s7access logs when you contact Customer Support.

AEM_Version Purging Basics

 

The Purge Version tool is intended for purging the versions of a node or a hierarchy of nodes in your repository.

 Its primary purpose is to help you reduce the size of your repository by removing old versions of your nodes.

Overview

The Purge Versions tool is available in the Tools console under Versioning or directly at:

http://localhost:4502/etc/versioning/purge.html

Start Path

• An absolute path on which the purge must be done. 
• You can select the Start Path by clicking the repository tree navigator.

Recursive

• When purging data you can choose between performing the operation on one node or on a whole hierarchy by selecting Recursive. 
• In the last case the given path defines the root node of the hierarchy.

Maximum versions to keep

• The maximum number of versions to be kept for a node. 
• When these number exceeds this value, the oldest versions are purged.

Maximum version age

• The maximum age of the version of a node. 
• When the age of a version exceeds this value, it is purged.

Dry Run

• Because removing versions of your content is definite and can not be reverted without restoring a backup, 
• thePurge Versions tool provides a dry run mode that allows you to preview the purged versions. 
• To launch a dry run of the purge process, click Dry Run.

Purge

• Launch the purge of the versions on the node defined by the Start Path.