TMF Reference Manual (G06.24+)

TMFCOM Commands
HP NonStop TMF Reference Manual—522418-002
3-210
RECOVER FILES
You can specify only one of the following options in the same RECOVER FILES
command: TIME, TOFIRSTPURGE, or TOMATPOSITION. If you enter more than
one of these options, an error message is generated.
SERIAL Option Considerations
TMF provides an easy way to recover all files associated with a particular online dump,
or a subset of those files. For this operation, enter the RECOVER FILES command
with the SERIAL option, specifying the serial number of the dump. As an example, the
following command recovers all files for the dump identified by serial number 110:
TMF 7> RECOVER FILES *.*.*, SERIAL 110
TIME and TOFIRSTPURGE Option Considerations
When you use the TIME option in a RECOVER FILES command, the value you enter
must be greater than the actual dump time by at least one second to ensure a proper
recovery; otherwise, TMF recovers no files.
Resetting the system date and time backward (to an earlier time) causes newly
generated audit records to appear to have been created earlier than audit records that
previously existed. A later file recovery using the TIME option might recover the
database to an undesirable state, because file recovery stops when it encounters the
first audit record generated after the time specified.
Under certain very unusual circumstances, file recovery with the TIME option might not
succeed and an event message will be logged to report the error. Such a situation
would occur, for example, if the AUDIT attribute was turned off immediately following
an online dump, and the recovery was then attempted. Because no timestamp would
exist in any record following the Online Dump End record, recovery to a specified time
Caution. If you specify the TIME, TOFIRSTPURGE, or TOMATPOSITION option in a
RECOVER FILES command, you must immediately make new online dumps of the data files
recovered. Without these new dumps, you no longer have file-recovery protection for those
files, and subsequent file-recovery operations can fail. In particular, if you later try to use old
online dumps to recover files to a point beyond the time that the last RECOVER FILES
command was issued, the file-recovery process fails during the redo phase and transmits EMS
message 175:
Encountered a File Hiatus record for audit file filename at
audit trail Index #index, SNO #sno, RBA #rba.
Caution. If there is no transaction activity on a system for up to 10 minutes after an online
dump of a file was taken, and you perform an undesirable change that either unaudits or
purges the file within that duration, a RECOVER FILES command using the TIME or
TOFIRSTPURGE option to recover the file to a point within that 10-minute period might not be
successful. For Enscribe files, this recovery might not be successful if the change involves any
file-label modification records (and not only unaudit or purge operations). The recovery might
fail with an error message or it might report that the file was recovered even though it was not.
For a successful recovery in this kind of situation, use the TOMATPOSITION option in the
RECOVER FILES command, specifying an RBA before the undesirable change was made.