Directory Service could not open Database

[luckyosime]

I have this error every now and then on my site servers.DIRECTORY SERVICE COULD NOT OPEN LOCAL DATABSE,IT IS INCONSISTENT.TRY TO CORRECT THE ERROR WITH DSREPAIR.NLM. each time i try to use dsrepair,it will hang with no response.This problem is scary cause when it happens ,users cannot log onto that server and it causes down time.From my observation it has lost its directory service by then.
How do i mitigate this problem,cause i am not happy re-installing the affected servers as our only option.

Thanks