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user9231434 wrote:SEveral methods in the rman guide (see tahiti.oracle.com) and also in "Oracle Database RMAN Backup & Recovery" by Hart and Freeman (Oracle Press). Depending on your needs, a couple of things come to mind immediately, and they are not mutually exclusive:
I am taking full backup every week end. But its taking a long time to complete as size of database is very big. Is ther any way to do backup fastly as parrallal processing . We are using RMAN. Kindly tell me some way.
1 - take a full (incremental 0) backup only once a week, with incremental (incremental 1) backups the other 6 days.
2 - backup only a subset of your tablespaces each day - different subset each day.
3 - implement change tracking, so rman only backs up blocks that have actually been modified
Also be aware
- you don't mention down time ... are you taking a cold backup? Are you aware that rman can do a hot backup, so you don't have to stop the database? Performance impact is usually pretty minimal.
- you must be in archivelog mode for any of the above.
user9231434 wrote:Ok, now we have a better understanding of where you are and exactly what you need to achieve. You've already been pointed to the relevant references. I just wanted to make sure you were 'asking the right question'. ;-)
Thanks for your reply, As our database running 24/7, I could do hot backup only. As you said , I take incremental level 0 backup at weekend only. This full backup only taking around 3 hours. I want to decrease the full backup time only.
There can be multiple level of contention in the case of backup.
You fist need to see where which section of the backup is making it slow.
1. Check the database. if you are not using Automatic Memory Mgmt then give Large Pool enough space to handle RMAN request.
2. Configure multiple RMAN Channels if possible.
3. Check the thoughput you are getting at the tape level (TSM in case you are using it)
Some time the thoughput at the TSM level is so low that no matter how much you tune your RMAN/Database, it won't help. I am sure I may be missing few other points that other members might have pointed out.
sb92075 wrote:With the built-in cache many modern devices have, this can sometimes be elsewhere than expected. Don't be afraid to try it even if it looks like it might not work or a rule of thumb tells you it won't.
Is is possible to make parrallel processing in morethan one disk or tape at the same time?How many disk controllers?
How many tape controllers?
Bottleneck will occur at slowest device; regardless of number of parallel streams feeding it.
Also be sure and stress-test - many of these devices will work fine until they hit a certain saturation, then go downhill fast just cause a little extra work started by, say, OS housekeeping.