| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> RE: ****** RMAN backup for multi TB databases ******
Hi Stephen,
Thank you very much for the details! Much appreciated!
When you recollect the rman parameter that sets how big the chunks of data are that it sends to Networker please let me know.
Best regards,
Sam
Stephen.Lee_at_DTAG.Com wrote:
I don't have anything as big as your situation, but I do have a box on which the rman backup sets for full backup total between 500 - 600 Gb. The limitation on speed here is the rate at which data can be tape written to the tape drives; and this depends on the number of drives and the number of I/O interfaces to the drives. If you are writing directly to tape, then you can experiment with the number of rman channels to open to get the writes to distribute over the drives and keep all of the drives busy writing. There is also an rman parameter that sets how big the chunks of data are that it sends to Networker. I forgot what it is.
Because of concerns about restore time when restoring directly from tape, we now run rman to backup to a 1.8 Tb filesystem created for this purpose, then use a ksh (We don't need no stinkin' Perl) script to copy the files to tape via Networker and delete the previous day's backup. The archived log backups get copied first. Our backup times run 3 hours to backup to disk and 7 - 9 hours to copy to four tape drives on two SCSI interfaces. I have maxpiecesize set to 5 GB for the datafile backups so that the I/O gets distributed more or less evenly among the tape drives. Archived log backups don't have maxpiecesize set because those backup sets usually total around 15 - 25 Gb.
The script for sending to files to tape can be found here: http://integrid.info/tape_copy.ksh
NOTE: One thing that should be fixed with the script -- one of these days when I get around to it (oh yeah, sure) -- is that while the script checks to see if it is already running with at least one of the command line args and exits if it is, it will run (I think) if there are no common command line args between the two commands. HOWEVER, both running copies will use the same log file. (I'm pretty sure the e-mail files will be unique.) I really should do something about that ... some time ... before the Vogons get here and bulldoze the planet away.
>-----Original Message-----
>I am concerned about
>backup time with full/cumulative/ incremental backups when
>RMAN is used in conjunction with Legato networker.
-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html ----------------------------------------------------------------- --------------------------------- Do you Yahoo!? Win 1 of 4,000 free domain names from Yahoo! Enter now. ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Mon Aug 23 2004 - 15:35:25 CDT
 |
 |