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Restoring A Segment

If your analysis indicates that the damage you need to recover from is isolated to a specific Pagestore segment, you can follow the steps in this section to recover just that segment. If you are not sure whether other segments are affected, the safest approach is to restore all segments.

To restore a segment, follow the procedure outlined below.

 

Task A Ensure That There Are No Pending Updates

You do this by varying the affected segment offline or shutting down the Data Object Broker. If segment 0 (the MetaStor) is to be recovered, you must shut down the TIBCO Object Service Broker system.

Be careful not to restore a segment to a point prior to the last physical definition change for any table held in that segment. Access errors can result when users attempt to use the table, since there can be a mismatch between the physical data and the recovered table definition.

Procedure

1.	Execute the command to vary a segment offline.

The command is as follows:

Modify dob_jobname,Dboffline=segmentname or segmentnumber

Examples:

Modify dob_jobname,Dboffline=3

Modify dob_jobname,Dboffline=sales

You can also vary a segment offline using the Administration menu. For more information about the various options on the Administration menu, refer to TIBCO Object Service Broker for z/OS Installing and Operating.

2.	Force a journal spin

When you vary a segment offline, a checkpoint is automatically taken. We recommend that you also force a journal spin to ensure that all database images are written out to the journal accumulation. You can force an immediate journal spin by issuing the following command from the z/OS operator console:

Modify dob_jobname,Spinsubmit=Immed

For more information about TIBCO Object Service Broker operator commands, refer to TIBCO Object Service Broker for z/OS Installing and Operating.

Task B Extract Parts of the Backup Relating to the Segment

Use a recent backup of that segment, or use a sort filter to read in your most recent full system backup and extract those parts relating to the specific segment.

For example, you can SORTIN an entire system backup, and SPINOUT only those pages belonging to segment 1. To selectively sort out a specific segment or page data set within a segment, you add an INCLUDE statement to your sort control cards.

This example sorts images for segment 1:

INCLUDE COND=(6,1,BI,EQ,X’01’)

This example sorts images for page data set 3 in segment 1:

INCLUDE COND=(6,1,BI,EQ,X’01’,AND,7,1,BI,EQ,X’02’)

Data sets are numbered from 0; therefore, the data set must equal hex ‘02’ to be filtered out.

Task C Rebuild the Selected Page Data Sets

This is described in Full Recovery Procedure.

Task D Bring the Affected Segment or Full System Back Online

The command to vary a segment online is:

Modify dob_jobname,Dboffline=segmentname or segmentnumber

You can also bring the segment back online from the Administration menu.

Copyright © Cloud Software Group, Inc. All Rights Reserved