On the System Status page of the LogLogic LMI appliance you may see that no chart information is being drawn for the current inbound message rate or the CPU utilization graphs. One possible cause for this is the need for more disk space.  If it's disk space-related then you will probably see a sys.log message like the following in /var/log/sys.log:

Aug 26 10:15:00 localhost MGMT: %LOGLOGIC-6 module:engine_lx_scheduler(9937);  file:lx_scheduler.c(CheckLXDiskUsage,371);  action:start; job:purge_lx_oldest_tables ;
Aug 26 10:15:00 localhost MGMT: %LOGLOGIC-6 module:engine_lx_scheduler(9937);  file:lx_scheduler.c(CheckLXDiskUsage,444);  action:lx_scheduler: Oldest table(ll_stats.mrgstatMessages15min_1249358400) time(1251950400 Thu Sep  3 00:00:00 2009 ) to be dropped to recover disk space. Disk space avail:21.42 GB, total:266.72 GB. ;
Aug 26 10:15:00 localhost MGMT: %LOGLOGIC-6 module:engine_lx_scheduler(9937);  file:lx_scheduler.c(CheckLXDiskUsage,444);  action:lx_scheduler: Oldest table(ll_stats.mrgstatCPUUsage5min_1250740800) time(1251345600 Thu Aug 27 00:00:00 2009 ) to be dropped to recover disk space. Disk space avail:21.42 GB, total:266.72 GB. ;

Note that the logs above are generated by the engine_lx_scheduler. Although this engine doesn't exist on an ST system, the equivalent engine engine_st_scheduler does exist and is the engine responsible for generating this event on ST appliances.