Re: RMAN, vanilla or "tweaked"

From: Joseph Amalraj <joseph_at_amalrajinc.com>
Date: 2006-01-12 23:14:23
Message-id: 20060112221423.17289.qmail@web308.biz.mail.mud.yahoo.com

Setting the BLKSIZE does help, I have set it upto 512K    

  also SIZE_DATA_BUFFERS and
  NUMBER_DATA_BUFFERS on the netbackup size also needs to be adjusted.    

  Increasing the number of channels helps to increase the backup speed but reduces the \ restore speed, because multiple channels are multiplexed on the tape.      

  Number of channels for the backup should match the total of multiplex configured in the \ Netbackup policy.    

  If disk i/o is tuned using SAME, maximum speed can be attained by using 1 channel per \ tape drive.    

  Filesperset is another RMAN parameter that can be tuned.    

  Oracle had released a white paper related to RMAN tuning and this is very informative.    

  Joseph Amalraj           

"Kline.Michael" wrote:

        st1\:*{behavior:url(#default#ieooui) }                          We are trying to \ 

squeeze out more performance on RMAN. The network folks said our back channel is only 60% \ used and NetBackup has found quite a few errors and corrected them.    

  What other settings other than more tape drives have you found to be very useful?    

  For instance, how many are tweaking the blksize on the allocate channel command and did \ it really help?    

  How many are messing with the backup_tape_io_slaves and what numbers worked and what \ numbers provided no help at all. I know on some things 4 may be WAY better than zero, but \ 10 provides maybe 2% more, thus useless.    

  Also, what kind of throughput is possible? We are doing about 22 to 30MB per channel \ thus far. But on one test pushed that to 47MB. How come we can’t push 47MB all the time?    

  We’ve got several databases in the multiple TB and at least once a week will need to do \ a full backup on.         Received on Thu Jan 12 2006 - 23:14:23 CST