Buffer Storage Usage Exceeds thershold

Dear All,

i found an alert in SAP Solution Manager.

100 % > 98 % (15 Min.) SAP buffer:buffer storage usage exceeds threshold

the same alert appear on Monday (09/09/2010), and i restart the SAP in the evening. But the alert appear again today..The buffer is filled up rapidly.

Please some one tell me what to do with this condition

and i also found this alert to in database monitored

*68 % < 90 %: cache hit ratio below threshold *

*799 < 4.000 redo entries per redo log space requests *

what does this alert means?

Im newbie in SAP 😔

thanks