10 Replies Latest reply on Jan 22, 2013 3:20 AM by TSharma-Oracle

    rman backup with archivelog from tape


      We are doing a level 0 backup on sunday and then level1 backup on all the weekdays.
      The archive logs generated are 1GB each and are more in number.
      IF we include archivelog in level1 backup , its taking around 12hrs to complete.
      So we are thinking of not including the archivelog in level 1 backup,but then we can daily move the archive logs to another location .
      So archivelogs will not be in the rman backup.

      So in case of restore, how can we apply the archive logs required? rman will not identify the archive logs...how can we manually apply the required archive logs

      Please help
        • 1. Re: rman backup with archivelog from tape
          My thoughts are maybe the Titanic can go faster without lifeboats too.

          I would not give up my Archive for anything.

          I would setup Data Guard and do backups from the Standby first.

          Best Regards

          • 2. Re: rman backup with archivelog from tape
            Hemant K Chitale
            Information about ArchiveLogs is available in the controlfile as I outlined in my response post in the thread How to find out which archived logs needed to recover a hot backup?

            However, if your CONTROLFILE_RECORD_KEEP_TIME is 7 days and you are attempting a restore of a backup 14 days or 28 days or 35 days old ... you may be out of luck.

            You'd need to maintain a listing of ArchiveLogs in some manner (e.g. a log file outside the database that you periodically update with information about ArchiveLogs).

            It is much better to also backup the ArchiveLogs using RMAN. Don't forget to ensure that controlfile backups or autobackups are also taken and retained.

            Hemant K Chitale
            • 3. Re: rman backup with archivelog from tape
              You can provide some more information to help you better.

              How much time Level 1 backup is taking with out archivelogs ?
              Have you enabled Block Change tracking to make the incremental backups faster ?
              If the number of archive-logs are more.. you can consider only archive log backups multiple times a day and ensure that they are also pushed to your backup medium..

              There are many ways to speed up the RMAN backups.. more information can be definitely helpful..

              • 4. Re: rman backup with archivelog from tape
                we havent tried without archivelogs.

                block change tracking is implemented.
                The backups are going to a NFS mounted disk.
                Can you let me know how to increase the performance of Rmanbackups.

                i have enabled backup optimization on , deleting archivelogs after backup, block change tracking enabled

                What i was also looking for is , if i am not including the archivelogs in rman backup and seperately taking backup of them, how do i use those during restore.
                • 5. Re: rman backup with archivelog from tape
                  Hi, you do not have to worry until you have all the archivelogs available. First you have to understand that what happens when you take the backup of archives using RMAN and than you restore it during recovery. Basically RMAN restores all the archive logs to the archive location first and than it starts applying.

                  So in your case you have all the archives already available so in this case you are saving RMAN's work. You just need to restore(by OS copying) your archives to the archive location. So while recovery RMAN will read your archives right from the archive location. It has all the information in the control file.
                  After restoring 0 level backup, RMAN will apply 1 level backups and than RMAN will check archives in archive location and read those from there. Hope this make sense to you.
                  • 6. Re: rman backup with archivelog from tape
                    For RMAn performance allocate multiple channels. This will parallelize your work load.

                    Please see this link also. This will help.

                    • 7. Re: rman backup with archivelog from tape
                      Hemant K Chitale
                      You have been given advice :
                      Hi, you do not have to worry until you have all the archivelogs available
                      The operative words are "HAVE ALL"

                      What if the disk or filesystem holding the archivelogs is corrupted / damaged / fails ? You'd be host with your own petard -- i.e. you'd be dead in the water.

                      What if you need to restore a copy of the database that is older than the oldest archivelog that you have on disk ? All backups older than the oldest available archivelog are useless.

                      Backup your archivelogs if you think that you want to keep your job.
                      Ask your manager if he thinks that the data is not important to the company. Ask the CEO if he thinks that he doesn't need that database.

                      Hemant K Chitale
                      • 8. Re: rman backup with archivelog from tape
                        Hi Hemant, If you see users original post, user mentioned that user is backing archivelogs to another location. it is just that user is not using RMAN to backup the archives.

                        I never said that do not backup your archives. I said as long as archives are available you can recover your database. "Available" itself means readily obtainable.
                        • 9. Re: rman backup with archivelog from tape
                          Hemant K Chitale
                          She is moving the archivelogs to another location. That would mean that the other location is a disk filesystem. That would have limitations on disk space. Older archivelogs would have to be purged. See my first response. If she needs to restore a database backup older than archivelogs still retained on disk, she's out of luck and cannot recover the database.
                          Just as the archivelog filesystem on the database server can be corrupted, so can the "other location".

                          Normally, with tape backups, I always ensure that I have two separate backups of archivelogs to tape.

                          Hemant K Chitale

                          Edited by: Hemant K Chitale on Jan 22, 2013 9:43 AM
                          • 10. Re: rman backup with archivelog from tape
                            I would again say 'as long as archive logs are available'. These days any cheap disk is as cheap as tape. As long as system administrator is taking backup of that disk..she should be good.