Solved

RMAN performance

Posted on 2012-03-19
6
565 Views
Last Modified: 2012-03-30
We have an ASM database on a P780 AIX with almost 72 data files and the DB size now is 200 GB
The backup started to take almost 3 hours the I have started to allocate 16 channels as following

RUN {
allocate channel d1 type disk ;
allocate channel d2 type disk ;
allocate channel d3 type disk ;
allocate channel d4 type disk ;
allocate channel d5 type disk ;
allocate channel d6 type disk ;
allocate channel d7 type disk ;
allocate channel d8 type disk ;
allocate channel d9 type disk ;
allocate channel d10 type disk ;
allocate channel d11 type disk ;
allocate channel d12 type disk ;
allocate channel d13 type disk ;
allocate channel d14 type disk ;
allocate channel d15 type disk ;
allocate channel d16 type disk ;
backup check logical as compressed backupset tag='DBPRO_rmanbackup_compressed'
database filesperset 1 plus archivelog;
crosscheck backupset;
crosscheck copy;
crosscheck archivelog all;
delete noprompt expired backup ;
delete expired archivelog all;
delete noprompt obsolete;
}


How can we improve this to be faster ?
Can we use maxopenfiles here?
Is using filesperset 1 correct here?
0
Comment
Question by:it-rex
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 77

Expert Comment

by:slightwv (䄆 Netminder)
ID: 37739231
Do you need to do a full backup every night?

I would suggest a rolling incremental with block change tracking:

4.4.3 Incrementally Updated Backups: Rolling Forward Image Copy Backups
http://docs.oracle.com/cd/B19306_01/backup.102/b14192/bkup004.htm

Then only blocks that have changed are backed up and the incremental is merged back into your level 0 (full) so you always have a full around.
0
 
LVL 11

Author Comment

by:it-rex
ID: 37739239
what if I want to improve this full backup.
before it used to be 1 channel and took 4 hours now with 16 channel  it went down to 1 and 40 minutes,I think we can do more.

thanks
0
 
LVL 77

Assisted Solution

by:slightwv (䄆 Netminder)
slightwv (䄆 Netminder) earned 200 total points
ID: 37739282
I've not messed a lot with tweaking a multiplexed backup.  I just do the rolling incremental and let RMAN take the defaults.

I would suggest you refer to the docs to answer your questions:

http://docs.oracle.com/cd/E11882_01/backup.112/e10642/rcmcncpt.htm#autoId15

Hopefully another Expert will stop by later that has done this.
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 29

Accepted Solution

by:
MikeOM_DBA earned 200 total points
ID: 37739347
...with almost 72 data files and the DB size now is 200 GB
That is an average of less than 3 GB per file!
Definitely try using a larger "files per set", perhaps 24 or more.

And if you have enough backup space, consider an "image copy" with daily incrementals.
Or...do the rolling incremental with block change tracking as slightwv suggest.

Also, instead of continuing to increase the number of data files in the database, increase the size of the existing files!
;)
0
 
LVL 48

Assisted Solution

by:schwertner
schwertner earned 100 total points
ID: 37744200
I guess you have reached the optimal speed of the backup for this 200 GB database.

To increase the speed use something like:

database filesperset 4

Next suggestion (if you can use independent devices outside the ASM):

Distribute the files accross devices:

http://www.dba-oracle.com/t_rman_distribute_backup_files.htm
0
 
LVL 11

Author Closing Comment

by:it-rex
ID: 37787291
Thanks all
0

Featured Post

MS Dynamics Made Instantly Simpler

Make Your Microsoft Dynamics Investment Count  & Drastically Decrease Training Time by Providing Intuitive Step-By-Step WalkThru Tutorials.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Truncate is a DDL Command where as Delete is a DML Command. Both will delete data from table, but what is the difference between these below statements truncate table <table_name> ?? delete from <table_name> ?? The first command cannot be …
Checking the Alert Log in AWS RDS Oracle can be a pain through their user interface.  I made a script to download the Alert Log, look for errors, and email me the trace files.  In this article I'll describe what I did and share my script.
This video explains at a high level with the mandatory Oracle Memory processes are as well as touching on some of the more common optional ones.
This video shows information on the Oracle Data Dictionary, starting with the Oracle documentation, explaining the different types of Data Dictionary views available by group and permissions as well as giving examples on how to retrieve data from th…

717 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question