Disk Storage Capacity Recovery - Northern Telecom DMS-100 Series Maintenance Manual

The index file tracks the data file versions. It may contain up to 56 (72-,
140-, and 380-Mbyte disk drives; 200 for 380-Mbyte w/56K polling and
760-Mbyte) versions. Each version of the index file consists of 9 bytes as
follows:
Table 2-1
Byte structure of index files
Byte
1
2-3
4-5
6, 7, 8
9
The total number of bytes in an index file is:
1 504 if there are 56 versions per index file; 9 bytes times 56 versions
2 1800 if there are 200 versions per index file; 9 bytes times 200 versions
The other static files (statistics, site data, program) are accumulated in 512
byte increments and put on disk.
Each DPP disk file has a number which represents the number of days left
before the file is deleted. This number is used for the message journal files
and secondary (polled) call record data files. The number is entered into the
file upon creation of the file on the disk. After the file has been polled, the
number is decremented by one at 1 a.m. of each day. The file is deleted
when:
•
the (down) count reaches zero, or,
•
when it is the oldest file on disk with AMA storage exceeding 90%, or
with AMA file versions exceeding 56, (or 200)
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Disk storage capacity recovery

When a disk full condition exists, the DPP does not write over stored
primary data. Instead, it switches to an only disk mode and continues
writing data to the other disk. When this disk becomes full, an EOT signal
is sent to the DMS-100. The DMS-100 attempts to access the second
interface. The second interface also returns an EOT to the DMS-100 and a
critical alarm is generated.
Note: To determine what percentage of the disk has been used, see the DISK
USAGE command in 297-1001-821.
DPP Recovery and Routine Maintenance Guide BCS35 and up
DPP system operation 2-9
Description
Version number
Total number of blocks
Number of blocks to be polled
Starting sequence number
Days to delete