Is there a way to control the number of backup files and the maximum log size for system.log.D* files?

Answer

Customer can control the number of backup files and the maximum log size for system.log.D* files using the parameters specified in log.properties file.
The properties for the SYSTEM and SECURITY logs are declared in log.properties. These can be overridden in customer_overrides.properties with prefix "logService". The properties governing the size and numbers of log files have been explained below:

systemlogger.rotatelogs = true
If this is set to false the below two attributes will be ignored and logger will continue to write in just one log file. Set it to true (Default value) to let the below properties take effect.

systemlogger.maxlogsize = 100000
This is the number of write operations after which the log messages will be logged in a new log file.(Default value is 100000 KB)

systemlogger.maxnumlogs = 10
Maximum number of log files. E.g. if this is set to 10, when the 11th log file is created, the first one will be removed.

These properties are honored for one cycle of server start to server shutdown.
Once the server is shutdown the Logging framework restarts and creates each of the log files from the beginning.