90% Disk Occupancy - Northern Telecom DMS-100 Series Maintenance Manual

reduced to the 70% threshold. As new primary files are added to storage,
the oldest secondary files continue to be deleted. If all secondary files are
deleted and disk occupancy remains at 70% or above, a minor alarm is
raised.
With Disk Capacity Enhancement
When the amount of primary data on the disks reaches 70% of total storage
capacity, a minor alarm is raised. No secondary data is deleted from storage
at this point.

90% disk occupancy

Without disk capacity enhancement
When the 90% disk occupancy threshold level is reached, all message
journal (LOG) files are deleted to provide additional space for AMA
records. If primary data occupancy then continues to exceed the 90%
threshold, a major alarm is generated.
With disk capacity enhancement
When occupancy reaches 90% of maximum disk capacity, the oldest
secondary file is deleted so that occupancy is reduced to below the 90%
threshold. As new primary files are added to the disk, the oldest secondary
files have been removed, the message journal files are deleted. If primary
data occupancy continues to exceed the 90% threshold, a major alarm is
generated.
100% disk occupancy
When occupancy reaches 100%, the DPP disks mode drops to a
nonredundant or ONLY mode. The active disk stops writing data and the
standby disk does not clear but overwrites data to accept new primary AMA
data. This cleared standby disk then becomes the active disk. Each hour, a
major alarm and log message are generated to notify personnel that the DPP
is in the ONLY mode.
In the extreme case that the second disk should be 100% full, and
end-of-tape (EOT) status is generated by the DPP. This causes the
DMS-100 to switch to the Data Stream Interface. The DPP responds with
another EOT status, forcing the DMS-100 to continue writing to an optional
parallel file. At this point, the DPP alarm is raised to critical status. In
compliance with Bellcore requirements that primary data not be overwritten,
no new data can be written to the DPP disk at this point.
Collecting data from a DPP in the nonredundant mode requires
extraordinary polling procedures, which are described in the DPP System
Maintenance Reference Manual, 297-1001-5290.
DPP Recovery and Routine Maintenance Guide BCS35 and up
DPP system operation 2-11