SCF Reference Manual for the Storage Subsystem (G06.24+, H06.03+)
Introduction to the Storage Subsystem
SCF Reference Manual for the Storage Subsystem—529937-007
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Manager Processes
Manager Processes
Storage Subsystem Manager ($ZZSTO) 
The $ZZSTO storage subsystem manager process is a generic process that uses SCF 
to perform persistent configuration and management. That is, when you use SCF to 
change the system configuration database, the changes survive a system load. After 
you configure storage subsystem objects online, $ZZSTO maintains this configuration 
information in the system configuration database ($SYSTEM.ZSYSCONF.CONFIG). 
You can use SCF to configure any storage device except the system disk while the 
system continues to do other processing. Configuration changes made online using 
SCF take effect as soon as the object is restarted and persist through processor and 
system loads (unless you load the system with a new configuration file). 
The storage subsystem includes features to manage both SCSI and Fibre Channel 
devices. The Fibre Channel features are collectively called the FCS Manager. FCS 
Manager assigns Fibre Channel loops for disk-drive enclosures to the FCS monitors. 
FCS Manager also passes OSM requests to the FCS Monitors.
The FCS Monitor Process
The FCS monitor process (FCSMON) is a persistent process that runs in every 
processor. FCSMON:
•
Monitors the Fibre Channel loops that connect to the disk-drive enclosures
•
Accepts requests from FCS Manager and notifies FCS Manager about disk-drive 
enclosure configuration information
•
Sends hardware change events and environmental status change events to 
$ZLOG
•
Polls disk-drive enclosures for drive insertions and removals
•
Polls the Environmental Management Units (EMUs) in the disk-drive enclosures
•
Issues commands to the EMUs
Storage Management Foundation (SMF) 
The Storage Management Foundation (SMF) uses SCF to help you manage data 
storage on multiple disks. Refer to the Storage Management Foundation User’s Guide 
for information about:
•
SMF configuration, management, and troubleshooting
•
File relocation
•
File protection and recovery
•
Other SMF utilities










