log_backup directory size & log rotation

[Hypertable user]

Dear all,

I just would like to know if it's possible to delete files under the "log_backup" directory. I have 9 range servers but 3 of them have a huge directory size.

[RS1] 195M    /opt/hypertable/0.9.8.8/run/log_backup/
[RS2] 198M    /opt/hypertable/0.9.8.8/run/log_backup/
[RS3] 197M    /opt/hypertable/0.9.8.8/run/log_backup/
[RS4] 193M    /opt/hypertable/0.9.8.8/run/log_backup/
[RS5] 285M    /opt/hypertable/0.9.8.8/run/log_backup/
[RS6] 173M    /opt/hypertable/0.9.8.8/run/log_backup/
[RS7] 3,5G    /opt/hypertable/0.9.8.8/run/log_backup/
[RS8] 2,1T    /opt/hypertable/0.9.8.8/run/log_backup/
[RS9] 45G     /opt/hypertable/0.9.8.8/run/log_backup/

My Hypertable is installed over Hdfs. Currently, my system is stable.
Is it possible to remove these files? Or Is there a configuration to limit the directory size?

Thanks for replies!