HP 3000 Manuals HP 3000 Manuals
Appendix E RECOVERY FROM SYSTEM FAILURE
OVERVIEW
If the system fails when a KSAM file is open for any type of access
except read-only, the file cannot be reopened until it has been
recovered. In such a circumstance, any attempt to reopen the file causes
the following message to be issued:
#192 -- SYSTEM FAILURE OCCURRED WHILE THE KSAM FILE WAS OPENED
The file is easily recovered in most cases by running KSAMUTIL.PUB.SYS
and then requesting KEYINFO. This command resets any incorrect
end-of-file marks and deletes any key values that point to non-existent
data records. If key values are missing or are out of sequence, the keys
cannot be recovered by KEYINFO and, in this case, the file must be
reloaded. (You can refer to section II for a discussion of KEYINFO; also
an example of file recovery and reloading is provided later in this
appendix,) If you want to examine the file statistics, you can run the
VERIFY command of KSAMUTIL using the NOCHECK option. (If KEYINFO does
not complete execution successfully, then the KSAM file must be
reloaded.)
For most purposes, this is all you need to know in order to recover a
file when a system failure prevents you from opening it. This appendix
provides internal details that explain why recovery is necessary and what
KEYINFO does in order to recover. It is intended primarily for the
sophisticated programming staff.