RDF System Management Manual for J-series and H-series RVUs (RDF Update 13)

NOTE: Because the remote mirrors will be connected to your standby system in the event of an
unplanned takeover, you should choose disk names that will not conflict with disks already connected
to the standby system.
ZLT is currently only supported with an HP StorageWorks XP disk array.
Assigning CPUs on the Standby System
By default, the same CPUs configured for each extractor on the primary system are used for the
corresponding extractor on the standby system, provided that both the necessary primary and
backup CPUs are available on the standby system.
If the necessary primary or backup CPU for an extractor is not available on the standby system,
the RDF monitor process selects from those CPUs that are available. If the monitor must select the
primary CPU for all extractors, it puts the primary processes of the extractors in as many different
CPUs as possible to achieve load balancing provided there are enough CPUs. If, for example, you
have six extractors configured, but you only have two CPUs on your standby system, the monitor
places the primary processes of three extractors on one CPU and the primary processes for the
other three extractors on the other CPU. If the monitor process selects the primary CPU of an
extractor and the configured backup CPU is not available on the standby system, then the extractor
does not run as a process pair; it only has the primary process.
RDF Configuration Attributes
RDF Remote Mirror Configuration
When declaring the attributes of the RDF configuration record, you use this optional attribute to
specify whether ZLT is enabled or disabled:
SET RDF REMOTE MIRROR [ ON | OFF ]
The default is off. If this attribute is off, normal RDF operations are unchanged, as is execution of
the RDF TAKEOVER command. If this attribute is on, then you must also set other RDF and extractor
attributes, and the TAKEOVER operation has an additional step: connecting the remote mirrors to
the standby system.
RDF Remote Standby Configuration
If you set the RDF REMOTE MIRROR attribute on, you must also set the system name of a standby
system. This standby system can be either a third system, apart from the primary and backup
systems, or it can be the backup system itself. The syntax for specifying the standby system name
is:
SET RDF REMOTE STANDBY node-name
node-name must be a valid name and must identify a system in your current Expand network. If
you set the standby to a different node than your backup system, the specified system must be
accessible to the backup system.
RDF Configuration Record Validation
When you ADD the RDF configuration record, these checks are performed:
• If you set the RDF REMOTE MIRROR attribute on, but did not issue a SET RDF REMOTE
STANDBY command, the ADD command fails.
• If you set the RDF REMOTE MIRROR attribute off and issued a SET RDF REMOTE STANDBY
command, the ADD command fails.
ZLT is only a feature of the RDF/ZLT product: you cannot add the RDF record with ZLT attributes if
you do not have the RDF/ZLT product installed.
Assigning CPUs on the Standby System 333