While suiciding the log can usually bring the server back online, it also frequently results in both physical and logical corruption in the database, because it bypasses the normal process of rolling back incomplete transactions in the log (and rolling forward completed transactions) that takes place during online recovery. Frequently, the resulting corruption is not encountered until a later time, and the connection with the earlier log suicide is not always recognized.
WARNING! Log suicide is highly risky, and is not recommended except in extreme cases.