Forum Discussion

danielsg's avatar
danielsg
Level 1
5 years ago

Veritas NetBackup for Oracle (Release 7.0) (2010070805)

Hi all,

First of all, I'm a software engineer. Not a DBA by profession. I'm not trained in Veritas NetBackup. I'm fully aware I'm not qualified/ideal/best person for the job. But you play the cards you're dealt with.

I'm supporting a proprietary system at customer site with PR and DR site. The data synchronization between PR and DR is handled by the system. 

The system's Oracle Database is managed by customer's backup team. RMAN performs backup to tape (TYPE SBT_TAPE)

Long story short, PR & DR becomes out of sync. I've been tasked to perform the "data sync". The solution, provided by system vendor, is to perform DB recovery on DR DB using PR DB backup. 

Questions
(1) Customer's backup team is able to extract PR DB backup from NetBackup Media Server. According to the backup team, the backup will be in "Netbackup" format. Will RMAN on DR DB recognizes the "Netbackup" format data files and add to catalog for recovery?

(2) If RMAN is unable to recognize the "Netbackup" format data files, I would be performing PR DB backup to disk for transfer to DR as per system vendor's solution.

  1. Day 1. Backup team performs full DB backup on PR
  2. Day 2. My team performs full DB backup (no catalog) on PR. Restore PR backup onto DR.
  3. Day 3. Backup team performs archive log backup on PR
  4. Day 4. My team performs archive log backup (no catalog). Shutdown PR DB. Restore PR archive log backup to DR.

For DB recovery onto DR, do I need the "Day 3" archive log backup done by Backup team?

(3) There's a big difference on the size of INPUT_BYTES and OUTPUT_BYTES of backup performed by backup team's RMAN script and the system vendor's RMAN script.

Is the difference due to "compression ratio"? 

Row 4 & 5 done using  system vendor's RMAN script. Refer v$rman_backup_job_details https://photos.app.goo.gl/A8xMh6HRD57RWPDy7

Refer RMAN script used by Backup Team https://1drv.ms/u/s!AkTxE55WB3XMir47jE1OJv326OJs_w?e=wpO2Jg

Refer RMAN script provided by system vendor https://1drv.ms/t/s!AkTxE55WB3XMir48KebjFfrcSxy1Lg?e=H6gxIe

7.1.x and Earlier
AIX
  • jnardello's avatar
    jnardello
    Moderator
    5 years ago
    NetBackup images are stored in a modified GNU tar format - modified to support multiplexing of the backup streams among other things. RMAN will not be able to read the images directly, NetBackup HAS to be involved if you're talking about its images. Yes, you could remove NBU from the equation and do a manual RMAN dump off of prod, then recover that to the DR system using its RMAN; whether that's easiest would be a question for your DBAs (and potentially your network folks if that dump has to run via a replication link instead of using shipped backup tapes). If NetBackup needs to be involved then yes, you're looking at doing a backup of prod via NBU, then getting those images to your DR site, importing them to that NetBackup Master, then having the DBAs kick off a recovery to the DR database system. Most experienced NBU admins would automate most of this via SLPs (Storage Lifecycle Policies), but you could do it manually if desired via standard file transfer tools & bpimport commands (or its equivalent NBU GUI options). As far as whether you'll need to involve archive file backups & restores, best to plan for it and then the DBAs can tell you whether you'll need it after you complete the initial restore. By the time you've restored the main backup to the DR system, if nothing new has changed on the prod database then there won't be any archive files to worry about anyway. If it takes you 3 days to do the restore or there's 500 GB of changes made during the restore period, then you'll have archives to deal with. Same deal with them as with the database backup itself - either involve NBU or don't depending on your DBAs, if you go the NBU route then it'll be the exact same thing you did with the database backup; it's all just data as far as NBU is concerned. =) Do note that you will NOT be able to do any of these restores via NBU itself. The NetBackup Database Agents are all just hooks into the native database backup tools, so it's going to be a DBA putting together the RMAN script on their side to do the actual restores - NBU just makes the data available for RMAN to access. Likewise, RMAN doesn't really know much about NBU - it's just a storage device (as you noted, SBT_TAPE). To answer your last question, yes assuming the same items are selected for backup any major size discrepancies are probably the result of compression getting involved. Best of luck ! Let us know if you have any other questions about the restore & we'll try to help.