VMS Help RECOVER, Qualifiers, /UNTIL *Conan The Librarian (sorry for the slow response - running on an old VAX) |
/UNTIL=time Specifies the ending date and time for an after-image or before- image recovery operation. Specify the date and time using either absolute time or delta time. See the OpenVMS Glossary for more information about specifying absolute or delta time. The /UNTIL qualifier functions as follows: o For after-image recovery, the /UNTIL qualifier specifies the date and time up to which the backup copy of the data file is to be restored. If you do not use the /UNTIL qualifier with after-image recovery, then all updates through the most recent update recorded in the after-image journal are restored. o For before-image recovery, the /UNTIL qualifier specifies the date and time to which the data file is rolled back. That is, all modifications to the data file from the present time to the time specified with the /UNTIL qualifier are removed. In most cases, you should use the /UNTIL qualifier with before- image recovery; if you do not, then all modifications recorded in the before-image journal are removed. If you are recovering a file that is also marked for recovery unit journaling, the following rules apply: o For applications using only one file, if the time specified with the /UNTIL qualifier (or the most recent modification in an after-image recovery if /UNTIL is not used) is a point at which there are no active transactions for the file, then the file is restored to the time specified by the /UNTIL qualifier. o If one or more transactions were active at the time specified by /UNTIL, only those modifications made within transactions that were completed (committed) on or before that time are applied to the file. For example, suppose you issue the command RECOVER/FORWARD/UNTIL=10:30 for the backup copy of a file marked for both after-image and recovery unit journaling. Then, the restored file will include all modifications that were made within those transactions that completed on or before 10:30. (The same rule applies to before-image recovery: only those modifications made within transactions that were completed before the /UNTIL time are included in the restored file.) o For applications using after-image recovery in which more than one file is associated with record streams connected to the same transaction, you should exercise care in choosing whether or not to use the /UNTIL qualifier. If you do not use the /UNTIL qualifier with the first backup copy that you restore with after-image journaling, you need only restore those files in the application that are corrupted or lost. In this case, do not use the /UNTIL qualifier with any of the files that you restore. However, if you do use the /UNTIL qualifier with the first file that you restore, then you must restore each file in the application, using the /UNTIL qualifier with the same time value for each file. If you do not use the same time value for the /UNTIL qualifier, then the modifications for one or more transactions may be restored to some of your files, but not to others. o For applications using before-image recovery in which more than one file is associated with record streams connected to the same transaction, use the /UNTIL qualifier with the command RECOVER/BACKWARD in order to specify a time to which the file is rolled back. Then restore each of the files in the application to the same time specified for the first file, in order to ensure that the modifications for one or more transactions are not restored to some of your files, but not to others. o If you attempt to recover a file used in a multifile application that uses more than one after-image or before- image journal, the journals must be recovered in their entirety to assure transaction consistency. If you use the /UNTIL qualifier, the recovered files may still be inconsistent. NOTE The /UNTIL qualifier is a positional qualifier. For example, if you enter the following command, the file FILE-1 will be recovered up to the present, and file FILE-2 will be recovered until "yesterday." $ RECOVER/FORWARD FILE-1,FILE-2/UNTIL=YESTERDAY
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