DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-540DISK (MSS Disk Circuit Pack)
9
DISK (MSS Disk Circuit Pack)
The TN1657 Disk circuit pack is p art of the Generic 3r Mass Storage System
(MSS). The MSS provides non-volatile storage for system software, translation
data, announcement data and program upd ate data. As shown in Figure 9-25,
the MSS consists of a Host Adapter circ uit on the UN332 MSS-Network Control
circuit pack (M SSNET), a Small Computer System Interface (SCSI) bus, a
TN1656 Tape circuit pack and the TN1657 Disk Drive c ircuit pack. The Disk Drive
acts as the primary storag e device and the Tape Drive serves as a b ackup
device.
The system is usually booted from the b ootimage stored on disk. The save
translation and save announcements commands save to disk the
memory-resident translation data and TN750-resident announcement data,
respectively. The backup disk command copies data from the d isk to the tape
for backup storage. The restore disk command cop ies data from the tape bac k
to di sk. Al l MSS co mpo nents resid e in t he SPE, or PPN con trol c arr ier (c arri er A
for a s impl ex SPE, c arri ers A a nd B f or a d upl icat ed SPE).
The Disk Drive circuit pack c ontains SCSI bus terminators, an industry stand ard
SCSI-based Disk Drive, and interface c ircuitry to the private b us to control the
LEDs, detect the presence of the c ircuit pack, and identify the vintage of the
hardware.
A -48V to +12V converter circuit on the Tape circuit p ack provides p ower for both
the Tape Drive and the Disk Drive. The presence of +12V on these circ uit packs
is monitored separately by main tenance software so that a failure of the +12V
converter on the Tape circuit pack c an be identified or ruled out as the source of
the problem when the Disk Drive loses + 12V power.
The Host Adapter Circuit, Tape circuit pac k, and Disk circuit p ack are treated as
separate, but related, maintenanc e objects (H-ADAPTER,TAPE , and DISK). S ince
the Disk circuit pac k is controlled by SCSI commands w hich are generated b y
the Host Adapter, prob lems with the Host Adapter can p revent communications
with the Disk. Whenever the Host Adapter is taken out of servic e by the busy-out
host-adapter command, or due to failure of a critical Host Adapter test, the Tape
and Disk maintenance objec ts are also placed in a maintenance busyout state.
MO Name (in
Alarm Log) Alarm Level Initial Command to Run1
1. In a system with a simplex SPE, the carrier does not have to be specified. In a system
confi gure d with dup lica ted SPEs, the c arrier (a or b ) must be sp ecif ied.
Full Name of MO
DISK WARNING test disk a|b long MSS Disk Circuit Pack
DISK MINOR test disk a|b long MSS Disk Circuit Pack