18 Guide to Index Corruption Recovery
297-6201-501 97Q3 Standard 02.01 July 1997
4. Display the summary of TOLCRD files in the new index. The presence
of the message, GOOD TOLIDX FILE, is positive indication that the
new TOL index file was correctly created. This can be verified by dis-
playing the summary of TOLCRD files in the index. Enter the com-
mand (at the terminal):
>FILET (cr)
System response:
TOL FILE: 04 VSNS, 003487 BLKS, 000078 TO POLL
SEQ: 000000 FIRST, 003445 PRIM, 003523 NEXT IN
VS 81: 3451 BLKS, 6 TO POLL, TOL SEQ :000000
Note that the number of TO POLL blocks in the new index has changed
from 42 to 78. This is an increase of 36 blocks. This is correct because
the index file now correctly includes version 82 (which contains 36
blocks of data TO POLL). Since the BMC is actively collecting TOL
data, the number of blocks in the index may increase by more than the
indicated difference of 36 blocks.
5. Display the closed TOLCRD versions in the new index. Verification
that the TOLCRD versions are now in the proper order (sequential and
contiguous) can be performed by displaying the closed TOLCRD files
in the index. Enter the following command (at the terminal):
>FILET.Z (cr)
System response:
VS 81: 3451 BLKS, 6 TO POLL, TOL SEQ :000000
VS 82: 36 BLKS, 36 TO POLL, TOL SEQ :003451
VS 83: 36 BLKS, 36 TO POLL, TOL SEQ :003487
If the index listing exceeds 26 files, it will be necessary to issue the
FILET.Z command to display the next group of 26 files, until the end of
the index file is reached.
Sequence numbers not incrementing properly
Sequence numbers should always be sequential and continuous. They
should increment from a lower number toward a higher number and should
never decrement. The beginning sequence number for an TOLCRD file
can be calculated by adding the beginning block number to the number
of blocks from the previous sequence number.
If version 106 of an TOLCRD file has a starting sequence number of 02747
and contains 2968 blocks, then version 107 should have a starting sequence
number of 05715 (the sum of version 106’s beginning sequence number,
02747, plus the 2968 blocks in version 106).
Recognition
If sequence numbers are decrementing instead of incrementing, or if the
sequence number is not the sum of the beginning sequence number of the
previous version and the number of blocks in the previous version, then
corruption has occurred. Incorrectly incrementing sequence numbers may
be observed by displaying a listing of the closed TOLCRD files in the
index. The system should also report BAD TOLIDX FILE.
1. Check the TOL Index File.
2. Display the summary of TOLCRD files in the index.
3. Check that the sum of the beginning sequence number for a version and
the blocks in that version correctly adds up to the next beginning
sequence number.
Graphically, the problem can be represented as show in the diagram below:
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