multiple driver trace/log files not created

Hi, 

We have a customer environment having IDM 4.7 on SLES. We see that the driver log files are not created in multiple files, like ad_1.log, ad_2.log.

We see only one file ad.log always. I tried to find if there is some settings on the driverset or driver level but not found. The limit is set to 2048.

I found that the below from documentation.

NOTE:If the file size limit is specified the trace file is created in multiple files. Identity Manager automatically divides the maximum file size by ten and creates ten separate files. The combined size of these files equals the maximum trace file size.

But this is not happening. This problem exists for all driver logs.

Is there some configuration missing?

Please let me know.

Thanks in advance.

-dk