Technical information
Technician’s Handbook
158
Checking a Redundant System
1. Log on to the maintenance terminal and select 
maintenance mode.
2. Enter the following commands (first from the active 
plane, then from the inactive plane):
FIL STAT RED Indicates whether the database on 
both drives are IN SYNCH, OUT OF 
SYNCH, or ISOLATED. The 
databases should be IN SYNCH. If 
both planes are not IN SYNCH, see 
Table 25: Status of Redundant File 
System on page 125.
Note: It takes approximately 15 
minutes for both planes to become 
synchronized.
DBMS STAT Checks the status of the initialized 
flag. The flag should be on. If the flag 
is off, enter DBMS SAVE (first from 
the active plane and then from the 
inactive plane).
DBMS CH F Checks the sanity and current status 
of the system. The number of 
detected errors should be zero. 
Otherwise, there is a problem with 
the database and immediate steps 
should be taken to begin recovery.
Note: Check the active and inactive 
planes. This step takes 60 seconds 
to complete.
3. Enter the following commands from the active plane:
SH ST AL Checks for system alarms. There 
should be no alarms. If alarms are 
present, see Flowchart 3: An Alarm is 
Present on page 120.










