We are running a Windows 2000 Server as a domain controller and file server. 2 weeks ago, the machine was running fine. Then, after a power-outage and a restart, the machine became sluggish and intermittently stopped giving out DHCP (this can be temp resolved with a restart usually). Windows Task Manager shows 100% CPU usage. The top resource hog under the processes tab in Task Manager are lsass.exe and snmp.exe, that is, unless rtvscan is running. In that case, rtvscan is running at over 127k.
Event Viewer shows no obviously-relevant issues. Additionally, searching Google for lsass CPU usage issues has not been helpful to me.
What steps can I take to troubleshoot this? I have unplugged it from the network for 15min to determine if this is an internal or external issue. The CPU usage remains at 100%.
EDIT - the power outage was long enough to drain the UPS, which resulted in an improper shutdown (because I am not running UPS software on the machine).