Excessive evmlog files under $CRS_HOME/evm/log

Hi

Any Expert can tell why there are so many excessive evmlog files with the format <Servername>_evmlog.yyyymm22_xx? What are these trace files?

The files generated are in binary format which are unreadable, it is observed that it generated 2x-40 files daily:

...

-rw-r-----    1 crs      oinstall     523376 Jan 07 00:41 itdibm13_evmlog.20120107
-rw-r-----    1 crs      oinstall     523368 Jan 07 01:22 itdibm13_evmlog.20120107_2
-rw-r-----    1 crs      oinstall     523328 Jan 07 02:03 itdibm13_evmlog.20120107_3
-rw-r-----    1 crs      oinstall     523304 Jan 07 02:45 itdibm13_evmlog.20120107_4
-rw-r-----    1 crs      oinstall     523304 Jan 07 03:28 itdibm13_evmlog.20120107_5
-rw-r-----    1 crs      oinstall     523376 Jan 07 04:09 itdibm13_evmlog.20120107_6
-rw-r-----    1 crs      oinstall     523328 Jan 07 04:49 itdibm13_evmlog.20120107_7
-rw-r-----    1 crs      oinstall     523368 Jan 07 05:31 itdibm13_evmlog.20120107_8
-rw-r-----    1 crs      oinstall     523200 Jan 07 06:14 itdibm13_evmlog.20120107_9
-rw-r-----    1 crs      oinstall     523416 Jan 07 06:55 itdibm13_evmlog.20120107_10