StorageTek Host Software Component 6 User Manual

1st ed., 6/30/04 - 312579601

The BACKup utility performs extensive error checking on CDS records, as well as 
comparison checking between primary and secondary copies of the CDS. 

Note: In order to run a back up correctly, all data sets currently defined to the HSC should 
be specified. This ensures that proper CDS selection and reservation occurs. 

If both copies of the data set are available and an I/O error occurs during the analysis 
phase of backup, the utility attempts to continue backup on the other copy unless the CDS 
keyword specifies the CDS that contains the error. If the CDS keyword specifies the 
control data set containing the error, the utility terminates. 

Depending upon the option that you select with the keyword OPTion, 

• a straight copy is made 
• a detailed block analysis is performed 
• a restart of the utility is performed. 

Copy data sets are made for use as analysis data sets to limit the hardware reserve placed 
on the control data set to an absolute minimum. Depending upon options selected, analysis 
of data blocks can be performed and block information modified before the data is written 
to the backup data set (SLSBKUP). 

A return code of eight (RC=8) can be expected if shadowing (a secondary CDS) is enabled 
and the secondary /FILE statement is not provided. A backup of the primary control data 
set will not be taken. 

If for any reason, a return code of eight (RC=8) occurs, the utility may be able to be 
restarted (refer to “How to Restart Backup” on page 224). 

The RESTore utility works in conjunction with BACKup by formatting the discrepancy 
blocks into control card statements and outputting them to the SLSAUDIT data set. When 
the HSC is reactivated after a backup and restore, the discrepancy control statements are 
input to the SLUADMIN program and AUDIt, UNSCratch, and UNSElect are performed 
to resolve discrepancies. 

Refer to “Restore Utility” on page 276 for detailed information on the RESTore utility.