SCF Reference Manual for the Storage Subsystem (G06.24+, H06.03+)

Managing Magnetic Disks
SCF Reference Manual for the Storage Subsystem—529937-007
7-7
Changing the Speed of a Revive Operation
Changing the Speed of a Revive Operation
While a revive operation is in progress, you can use the ALTER command to change
the speed of a revive operation.
Considerations for Changing the Speed of a Revive
Operation
•
The speed of all future revive operations is also changed.
•
During system installation, the system administrator should tailor the
REVIVEPRIORITY and REVIVERATE attributes for your system. The default
values provided by SCF are acceptable for most environments:
°
REVIVEPRIORITY 50
°
REVIVERATE 100 second between copies
The default values minimize potential interference with system performance but
could result in revives that take too long to finish. (The longer the revive operation
takes, the longer your mirrored disks have dissimilar data.)
•
To speed up the revive operation (even though this change might slow system
performance), increase the REVIVEPRIORITY value and/or increase the
REVIVERATE value.
•
If you change these values while a revive operation is in progress, the disk process
does not restart the revive operation from the beginning but continues from the
point at which you entered the new values.
Example of Changing the Speed of a Revive Operation
This command establishes a revive priority of 60 and specifies that 90 megabytes of
data be revived between preemption checks while a revive operation is in progress:
-> ALTER $DATA01, REVIVEPRIORITY 60, REVIVERATE 90
Stopping a Revive Operation
It is seldom necessary to stop a revive operation (with a STOP DISK command on the
disk being revived) unless you want to force the revive operation to restart from the
beginning.
You might want to adjust a revive operation if:
•
System performance is degraded. See Changing the Speed of a Revive Operation
on page 7-7.
•
A media error has occurred, causing a defective sector.