1684452 - Cannot start after a crash or system restart: UNKNOWN State

After an operating system restart or a system crash, the SAP MaxDB/liveCache database does not start anymore. When you try to start it up or query its status with DBM command db_state, you receive an error similar to:

Error! Connection failed to node sap011 for database JDI:
-24700,ERR_DBMSRV_NOSTART: Could not start DBM server.
-24832,ERR_SHMNOTAVAILABLE: Shared memory not available
-24686,ERR_SHMNOCLEANUP: Could not cleanup the DBM server Shared Memory
-24606,ERR_SHMSO: Start address 0x349300010c1d01b8 for linetype 0 out

Or

-24576 DBMSrv   ERR_SHMNOHOUSEKEEPINGLYT: Could not create line layout for HouseKeeping
-24700 DBMSrv   ERR_DBMSRV_NOSTART: Could not start DBM server.
-24724 DBMSrv   ERR_RESLOCK_NO_LOCK: Resource ParamAccess not locked
-24726 DBMSrv   ERR_SHMLINESEXCEEDED: Too many lines of type 2
-24686 DBMSrv   ERR_SHMNOCLEANUP: Could not cleanup the DBM server Shared Memory

Or

DBM Server exits!
-24525,ERR_TOO_MANY_DBMSERVER_STARTED: Too many dbmserver processes have been started (nnnnnnnnnn registered, nnn allowed)

Error! Connection failed to node (local) for database SDB:
Connection broken to PID nnnn (D)

Or in log file 'dbmsrv_<server_name>.prt':

ERR     -24576 DBMSrv   ERR_SHMNOHOUSEKEEPINGLYT: Could not create line layout for HouseKeeping
ERR     -24700 DBMSrv   ERR_DBMSRV_NOSTART: Could not start DBM server.
ERR     -24724 DBMSrv   ERR_RESLOCK_NO_LOCK: Resource ParamAccess not locked
ERR     -24726 DBMSrv   ERR_SHMLINESEXCEEDED: Too many lines of type 2
ERR     -24686 DBMSrv   ERR_SHMNOCLEANUP: Could not cleanup the DBM server Shared Memory

Or

If you try to query database status with DBM command db_state

•    dbmcli -d <database_name> -u <dbm_operator>,<password> db_state

database status appears as 'UNKNOWN'.

Or it can't even connect to the database while it is still running:

Error! Connection failed to node (local) for database LCA:
Connection broken to PID 2336 (D)

Or the number of dbmsrv-processes is reported as invalid/corrupted when you try to establish a DBM session or execute a DBM command:
DBM Server exits!
-24524,ERR_INVALID_NUMBER_OF_REGISTERED_DBMSERVERS: The number of registered dbm server processes is corrupt (-235012096)
Error! Connection failed to node (local) for database SDB:
Connection broken to PID 6068 (D)

OS Platforms:

• Microsoft Windows Platforms (2003, 2008, etc..)
• Unix (AIX, HP-UX, SOLARIS, etc..)
• Linux (SuSe, RedHat, etc..)

Database Versions

• 7.5 (both 32 and 64bit)
• 7.6 (both 32 and 64bit)
• 7.7 (both 32 and 64bit)
• 7.8 (both 32 and 64bit)
• 7.9 (both 32 and 64bit)

runtime, maxdb, livecache, startup, crash, restart, ERR_SHMNOTAVAILABLE, ERR_DBMSRV_NOSTART, ERR_SHMNOCLEANUP, ERR_SHMSO, dbm_server, connection_broken, operating_system, start, shared_memory, Live_Cache, server, hang, standstill, connection, pipe, ipc, dbm, kernel , KBA , BC-DB-SDB , MaxDB , BC-DB-LVC , liveCache , BC-DB-LCA , liveCache Applications , BW-SYS-DB-SDB , BW on MaxDB , Problem