StorageTek Host Software Component 6 User Manual

Page of 718
50   VM/HSC 6.0 System Programmer’s Guide
1st ed., 6/30/04 - 312579601
primary copy. If a standby CDS copy is active, the new primary CDS copy is copied 
over the standby CDS copy, and the standby becomes the new secondary copy. 
• If a standby CDS copy is active, and a failure occurs in accessing the secondary CDS 
copy, the current primary CDS copy is copied over the standby CDS copy, and the 
standby becomes the new secondary copy.  
To utilize full automatic CDS recovery capabilities of the HSC, StorageTek recommends 
that all three CDS copies (primary, secondary, and standby) should be used. CDS copies 
must be created (by the SLICREAT program), defined to the HSC (by the CDSDEF 
control statement in PARMLIB), and active (by the CDs Enable/Disable command). CDS 
copies should be located on different DASD volumes for redundancy. 
For more details about automatic CDS recovery, refer to
 
“Control Data Set Recovery” on 
page 49
 
and “CDS Recovery Capabilities” on page 439
.
Automatic Recognition of Configuration Changes 
Some changes to the library configuration are automatically recognized by the HSC. 
Automatic Update of LSM from 4410 to 9310 
When an LSM comes online, the LSM type is reported to the HSC by the LMU. If the 
LSM is defined in the CDS as a 4410, but it is actually a 9310 (PowderHorn), the LSM 
type is automatically updated in the CDS. Thus, an LSM upgrade from a 4410 to a 9310 is 
automatically recognized and recorded in the CDS without running the Reconfiguration 
utility. 
Note: Replacing a 9310 with a 4410 LSM does not result in an automatic update of 
the LSM type. (In some cases the hardware report of this change may not be 
accurate.) 
If an LSM is defined to the HSC as a 9310, but it is actually a 4410, the HSC 
manages it without problems, since the panel configurations and LMU requests and 
responses are the same for 4410 and 9310 LSMs. However, HSC preferencing by 
LSM type will not work correctly using MNTD SCRDISM(CURRENT/ARCHIVE) 
for scratch dismount requests. 
Run-time Recognition of 9740 CAP Configuration 
The 9740 CAP can either be a 14-cell array, or it can hold a 10-cell removable magazine. 
The HSC recognizes the current CAP size when the LSM is modified online. This allows 
the user to change the 9740 CAP configuration without running the Reconfiguration utility 
or recycling the HSC. 
 
Using the SET Utility Instead of LIBGEN and Reconfiguration 
Changing a configuration using the Reconfiguration utility requires a global outage. Many 
of the changes made by the SET utility can be performed while HSC subsystems are up