RDF System Management Manual

Zero Lost Transactions (ZLT)
HP NonStop RDF System Management Manual—524388-003
16-8
Extractor Audit Trail Configuration
Extractor Audit Trail Configuration
When configuring RDF for ZLT, you must add the complete set of audit-trail volumes to
which RDF-protected data volumes are configured. For example, if your RDF configur-
ation only protects data volumes configured to the master audit trail (MAT), you must
specify all audit-trail volumes that are configured in TMF for the MAT (active, overflow,
and restore). Because each audit trail can have up to 16 active, 16 restore, and 16
overflow volumes, an extractor list can contain up to 48 volume names. You set each
volume name as follows:
SET EXTRACTOR VOLUME volume-name
volume-name must be a valid volume name specified in the current TMF configura-
tion on your primary system. Use a SET statement for each individual volume. You do
not need to specify whether the volume is an active volume, restore volume, or
overflow volume; you merely specify the volume name. The list of volumes you specify
is placed in the extractor configuration record.
When you ADD the extractor attributes, RDFCOM checks to ensure that each
configured volume is a valid volume. If any are not, the ADD command fails with an
error for the first volume name that is either an invalid name or does not correspond to
a valid volume.
ALTER RDF Remote Mirror Configuration
You can alter the RDF REMOTE MIRROR configuration attribute to turn ZLT protection
on and off as needed. If entered on the primary system, you must stop RDF, alter the
attribute, and then restart RDF. If the primary system is no longer available and you are
preparing to start the RDF takeover operation, you can alter the attribute on the backup
system. The syntax is as follows.
ALTER RDF REMOTE MIRROR [ ON | OFF ]
If you issue the ALTER command on the backup system while the network is down and
the primary system is still up, you must then issue the ALTER command again on the
primary system when the network comes back up; otherwise, the change will not be
kept on either the primary or the backup system.
If one of your remote mirrors fails during normal operations on your primary system,
you might want to turn the RDF REMOTE MIRROR configuration attribute off on the
primary system so that if you need to execute a takeover operation you can complete
the takeover as quickly as possible. Remember, if you have the RDF REMOTE
MIRROR configuration attribute turned off at the time of a takeover, you do not have
ZLT protection. When the troublesome mirror comes back up and is fully revived so
that it is current with the local mirror, you then re-enable ZLT on the primary to reinstate
ZLT protection.