There is no any log in the server.log after changing periodic-rotating-file-handler to size-rotating-file-handler.
The reproduce steps:
1. remove the part periodic-rotating-file-handler in standalone.xml
<periodic-rotating-file-handler name="FILE">
<formatter>
<pattern-formatter pattern="%d

%-5p [%c] (%t) %s%E%n"/>
</formatter>
<file relative-to="jboss.server.log.dir" path="server.log"/>
<suffix value=".yyyy-MM-dd"/>
<append value="true"/>
</periodic-rotating-file-handler>
2. add one size-rotating-file-handler
<size-rotating-file-handler name="FILE" autoflush="true">
<formatter>
<pattern-formatter pattern="%d

%-5p (%c) [%t] %s%E%n"/>
</formatter>
<file relative-to="jboss.server.log.dir" path="server.log"/>
<rotate-size value="500k"/>
<max-backup-index value="15"/>
<append value="true"/>
</size-rotating-file-handler>
3. start the jboss server, then you will see there is a warning in the server.log and no any further logs in the server.log.

13:23:28,205 WARN [org.jboss.as.logging] (Controller Boot Thread) JBAS011511: Replacing handler 'FILE' during add operation. Either the handler type or the module name differs from the initial configuration.

The possible fix:

https://issues.jboss.org/browse/WFLY-178 the code change is in https://github.com/wildfly/wildfly/pull/4137
and the bugzilla is in EAP6.1.0:
https://bugzilla.redhat.com/show_bug.cgi?id=918103

But this issue still exists in 6.1.1

Best Regards,
Vicky