You can redirect the CRM messages from JIRA logs to another one log file. It requires a JIRA restart.
In JIRA config file:
/opt/atlassian/jira/atlassian-jira/WEB-INF/classes/log4j.properties
Add following:
log4j.appender.crmfilelog=com.atlassian.jira.logging.JiraHomeAppender
log4j.appender.crmfilelog.File=crm.log
log4j.appender.crmfilelog.MaxFileSize=20480KB
log4j.appender.crmfilelog.MaxBackupIndex=10
log4j.appender.crmfilelog.layout=com.atlassian.logging.log4j.FilteredPatternLayout
log4j.appender.crmfilelog.layout.ConversionPattern=%d %t %p %X{jira.username} %X{jira.request.id} %X{jira.request.assession.id} %X{jira.request.ipaddr} %X{jira.request.url} [%c{4}] %m%n
log4j.appender.crmfilelog.layout.MinimumLines=6
log4j.appender.crmfilelog.layout.FilteringApplied=true
log4j.appender.crmfilelog.layout.ShowEludedSummary=true
log4j.logger.ru.teamlead.jira.plugins= INFO, console, crmfilelog
log4j.additivity.ru.teamlead.jira.plugins= false
And then restart JIRA.