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

5. Confirm that the disk has started:
-> STATUS $DISK00
Resetting a Group of Disks
1. Identify disks that have paths that are not running:
-> STATUS DISK $*-*, SEL NOT STARTED, SUB MAGNETIC
2. Prepare all nonrunning disk paths for a subsequent START command:
-> RESET DISK $*
3. To prevent a START DISK command with a wild-card disk name from failing if some disk paths
do not start:
-> ALLOW ALL ERRORS
4. To prevent a specified disk path from starting:
-> ABORT DISK $disk00-P
5. Start all startable disks:
-> START DISK $*, SUB MAGNETIC
Sparing a Defective Sector
Sector sparing is the process of moving the data on a physically defective sector to a different
sector and preventing data from using that defective sector again. A disk sector can be spared in
two ways:
• “Enabling Automatic Sector Reallocation” (page 104)
• “Sparing a Sector Manually” (page 105)
Automatic Sector Reallocation
If automatic sector reallocation is enabled (the default), the system automatically spares defective
disk sectors when detected. The INFO, LOG command displays spared sectors.
Automatic sector reallocation is controlled by the $ZRD9 process. This generic process starts
automatically when you load the system and continuously searches for media error events on every
sector on every disk in the system.
When automatic sector reallocation finds a media error event, it starts the $ZARS process. $ZARS
spares the bad sector, updates the system’s internal database, and continues to run as long as
media error events are reported. When no more media error events are reported, $ZARS stops.
Displaying Information About Automatic Sector Reallocation
To determine whether automatic sector reallocation is enabled on your system, at the TACL prompt:
> STATUS $ZRD9
System \COMM
Process Pri PFR %WT Userid Program file Hometerm
$ZRD9 0,381 150 015 255,255 $SYSTEM.SYS00.EMSDIST $ZHOME
Swap File Name: $SYSTEM.#0
Current Extended Swap File Name: $SYSTEM.#0
$ZRD9 B 1,372 150 001 255,255 $SYSTEM.SYS00.EMSDIST $ZHOME
Swap File Name: $SYSTEM.#0
Current Extended Swap File Name: $SYSTEM.#0
Enabling Automatic Sector Reallocation
To enable automatic sector reallocation:
-> START PROCESS $ZZKRN.#ROUTING-DIST
104 Managing Disks