Installation guide

Glossary
Manual Number 775012 G-9
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Note
The standby rebuild will only happen on the SAME
DAC960 controller, never across DAC960 controllers.
A “Standby” disk can be created in one of two ways:
1. When a user runs DACCF utility, all disks attached to the controller
that are NOT configured into any drive group will be automatically
labeled as “standby” drives.
2. A disk may also be added (attached at a later time) to a running system
and labeled as standby by using the “DAC960 Software Kit” (see
appropriate chapters for DAC960 utilities for a particular operating
system).
During the automatic rebuild process, system activity continues as normal.
System performance may degrade slightly during the rebuild process.
To use the standby rebuild feature, you should always maintain a standby
SCSI disk in your system. When a disk fails, the standby disk will
automatically replace the failed drive and the data will be rebuilt. The system
administrator can disconnect and remove the bad disk and replace it with a
new disk. The administrator can then make this new disk a standby.
The standby replacement table has a limit of 8 automatic replacements in any
session (from power-on/reset to the next power-off/reset). When the limit of
8 is reached and a disk failure occurs, the standby replacement will occur but
will not be recorded in the replacement table.
To clear the ‘standby replacement’ table, reboot the system from a DOS
bootable floppy, run the configuration utility and select the option ‘view/
update configuration’ from the main menu. A red box labeled ‘Drive Remap
List’ will be displayed. Selecting the box will allow you to continue. You
should save the configuration without making any changes, and exit the
configuration utility. This will clear the replacement table. You may now
proceed to boot your system and continue normal operations.
In normal use, the replacement table limit of 8 should not cause any
problems. Assuming that a disk fails about once a year (drives we support
generally come with a 5-year warranty), the system would run continuously
for a minimum of 8 years before the table would need to be cleared.