RDF/IMP, IMPX, and ZLT System Management Manual

Zero Lost Transactions (ZLT)

HP NonStop RDF/IMP, IMPX, and ZLT System Management Manual—524388-002

16-8

Error Conditions

If the standby system is different from the backup system and the monitor cannot reach

the standby system to start the extractor(s), the takeover operation aborts. If that

happens, you must bring the standby system up (and make sure it is available to the

backup system by way of the Expand network) and then reissue the TAKEOVER

command.

If an extractor cannot find an audit file it needs because the disk has not yet been

mounted, the extractor abends and the takeover operation aborts. If you have not yet

mounted the disk the extractor needs, you must mount it before reissuing the

TAKEOVER command. If the remote mirror cannot be mounted and you want to do

the takeover without the ZLT guarantee, you can alter the RDF REMOTE MIRROR

attribute on the backup system to off. When you reissue the TAKEOVER command,

the takeover then proceeds as a normal takeover operation (without ZLT).

STATUS RDF

You cannot issue the STATUS RDF command from the standby system; it must only

be issued from the backup system.

If a takeover does not involve ZLT, the extractor is not included in the STATUS display

during an RDF takeover operation. With ZLT configured and enabled, the STATUS

RDF display changes during an RDF takeover. During phase 1 (ZLT processing),

status is displayed for the extractor(s), consisting of process name, sno, rba, cpus,

error. The RTD field, however, is left blank.

RDFCOM INFO and SHOW Commands

The INFO command output includes the RDF and extractor configuration attributes for

ZLT, as does the output for the SHOW command.

Old Audit Trail Files

When a ZLT takeover operation completes, you should not purge the old audit-trail files

on the remote mirrors connected to the standby system if you believe you can recover

the primary system. The old audit-trail files are necessary for recovering the primary

system.

If you can’t recover the primary system, you may purge the files because they have no

further use.

Because the old audit-trail files are not managed by TMF on the standby system, if you

choose to purge them you must do so manually using Snoop.