SCF Reference Manual for the Storage Subsystem (G06.28+, H06.05+, J06.03+)

NOTE: When ownership of both SACs is lost, a read from one or both paths detects a loss of
ownership. However, a read from one path whose SAC ownership was not lost would not detect
the loss of ownership of the SAC on the path to the other disk.
PRIMARY Command Function in G05.00 and Earlier
On G05.00 and earlier RVUs, the PRIMARY command changes SAC ownership.
Before the PRIMARY command is issued, the status of $D0203 is:
STORAGE - Status DISK \WAGER.$D0203-*
LDev Path Status State Substate Primary Backup
PID PID
105 PRIMARY ACTIVE STARTED 2,22 3,16
105 BACKUP INACTIVE STARTED 2,22 3,16
105 MIRROR ACTIVE STARTED 2,22 3,16
105 MIRROR-BACKUP INACTIVE STARTED 2,22 3,16
In the figures that follow:
• SACs owned by processor 2 are shaded.
• Disk processes that are primaried in processor 2 are shaded.
• Primary paths are the bold lines.
• Backup disk processes are represented with a prime mark, such as $D0201'.
128 Disk Load Balancing