RDF/IMP and IMPX System Management Manual (RDF 1.4+)

Managing RDF
HP NonStop RDF/IMP and IMPX System Management Manual—524388-001
5-20
Monitoring Takeover Outcome
The following example shows how to use the TAKEOVER command when RDF is
running with updating enabled. The command sequence in the example causes the
backup system \TORONTO to take over processing from the primary system
\SANFRAN.
1. At the TACL prompt on the backup system (\TORONTO), start an RDFCOM
session and specify the control subvolume name:
>RDFCOM SANFRAN
2. At the RDFCOM prompt, issue the TAKEOVER command:
]TAKEOVER
RDF displays the following prompt message:
*** TAKEOVER assumes a disaster on \SANFRAN has occurred.
Are you sure you want to TAKEOVER?
3. To proceed with the takeover operation, enter Y or YES.
To abort the takeover operation, enter N or NO.
After you enter your response, RDFCOM returns its prompt. Then you can use the
STATUS RDF command to determine the status of the takeover operation. If the
takeover operation is still in progress, RDF displays the current state as
“TAKEOVER IN PROGRESS.”
When the takeover operation finishes, RDF displays a message such as the
following in response to the STATUS RDF command:
STATUS RDF (\RDF04 -> \RDF06) is NOT running
An RDF TAKEOVER has completed
Safe MAT position is SNO 1, RBA 87876660
MAT position for File Recovery: SNO 1, RBA 87876740
Monitoring Takeover Outcome
You can monitor the status of RDF takeovers by issuing a STATUS RDF command on
the backup system or by examining the events in the EMS log.
When all of the updater processes have stopped, the purger logs either a message
724 or 725 and then stops. Message 724 indicates that the takeover completed
successfully. Message 725 indicates that it did not, and you should reissue the
TAKEOVER command. A message 724 is always followed by a message 735, which
indicates the last MAT position seen by the receiver process. (Note that the 735 event
is used primarily for triple contingency.) These events will be followed by either an 888
or 858 event. See Takeover and File Recovery for more information.
For RDF network takeover considerations, see Section 13, Network Transactions.
For super fast takeover, see Tips for Executing Fast Business Takeover Operations in
section 1.