The Sensor (idsm2, nm-cids, 4215) lock up occurs so that you cannot log into the Cisco Admin account. Sometimes you cannot log into the service account either.
This issue occurs when the hard disk drive (HDD) for these platforms is not allowed to spin down at least once a day. When the HDD is continually used for long periods of time (weeks), the HDD heads become out of sync. This Sensor eventually reaches a lock up state that does not allow you to login. Sometimes there are HDD I/O errors in the Sensor logs.
For a workaround:
Power off the Sensor from which the IDSM2 blade must be pulled from the switch for 20 minutes and then power it on again.
Download and upgrade the IDS software to version 5.0(6), 5.1(2) or later for a permanent solution.
Note: If the software used is 5.0(6) or later, the sEventStore/WerrWarning Event store circular buffer may be in an invalid state, recoveringerror message is also found in the Show tech or cidDump on the Cisco IDS, which occurs because of database index rebuild.
Cannot communicate with authenticationApp (getUserAccountConfig). Please contact your system administrator