Activities In Response To Disk Mode Message(S) - Northern Telecom DMS-100 Series Maintenance Manual

Table 3-1
Disk drive modes
Mode Description
AO A ONLY
The DPP processors read data from and write data to the disk in the A processor
chassis ONLY .
AP A PRIME
The DPP processor writes duplicate information to both disks (A and B). The disk
in the A chassis is the PRIME disk and the active processor reads data from that
disk and accesses the disk in the B chassis at about the same time; writes to the
PRIME unit first.
BO B ONLY
The DPP processors read data from and write data to the disk in the B processor
chassis ONLY .
BP B PRIME
The DPP processor writes duplicate information to both disks (A and B). The disk
in the B chassis is the PRIME disk and the active processor reads data from that
disk and accesses the disk in the A chassis at about the same time; writes to the
PRIME unit first.
NONE 1 NO MODE
The DPP can't access any disk for read or write functions. This indicates:
a. a failure to set up the disk mode at the factory (initial installations)
b. a hardware failure such as improper installation cabling, rough handling of
Notes:
Note 1: S/W LOADED message cannot appear if the disk mode is NONE.

Activities in response to disk mode message(s)

Analyze the conditions above in relation to the printout obtained. Further
action may be required to obtain optimum disk drive performance. Return
to the procedure for the message originally printed and resume Craftsperson
Activity, or proceed to Disk Drive Recovery Procedure.
the disk drive assembly, or a PCA failure.
DPP Recovery and Routine Maintenance Guide BCS35 and up
Disk drive overview 3-3