Each device (or emulator) instance writes its own log into its directory. See Device Names to correlate the directory number and the device name.
WindowsC:\Documents and Settings\user\Application Data\javame-sdk\version\work\emulator-instance\device.log
Mac OS/Users/uname/Library/Application Support/javame-sdk/3.0/work/ emulator-instance/device.log
The verbosity of the device instance log is controlled by the log4j.xml file, as described in Device Manager Logs.
A priority value for the categories com.sun or VM can be set to the following levels: ERROR, WARN, INFO, DEBUG, TRACE (ordered from least to most verbose. The verbosity of the device instance log is controlled by log4j.xml, as described in Device Manager Logs.