Solved

Consultation for changing the parameter MEMORY_TARGET

Posted on 2015-01-12
6
174 Views
Last Modified: 2015-01-12
Hi experts,
In a RAC ASM 11g, Linux  (RedHat  2.6.18), with 2 instance, I need to modify:
memory_max_target parameters (static parameter) 
memory_target (dynamic).

Open in new window

Both in 8G ( currently have 6G)
I received a recommendation that tells me tweak in /etc/fstab:
 /dev/shm ----> defaults, size = 8G,

Open in new window

and then:
mount -o remount / dev / shm

Open in new window

In addition to the statements:
ALTER SYSTEM SET MEMORY_MAX_TARGET = 7680M SCOPE = SPFILE; 
ALTER SYSTEM SET MEMORY_TARGET = 7680M SCOPE = SPFILE; 

Open in new window

then, in both nodes:
shutdown immediate
startup

Open in new window

Currently the line in fstab says:
tmpfs /dev/shm tmpfs defaults, nosuid, nodev 0 0

Open in new window

Is it necessary to make this change in the fstab?
Would appreciate a look from you and the basic steps to perform the task.
Thank you very much
Regards
0
Comment
Question by:carlino70
  • 3
  • 3
6 Comments
 
LVL 73

Expert Comment

by:sdstuber
Comment Utility
yes, you need to make your tmpfs large enough to hold your MEMORY_MAX_TARGET.

You are trying to hold 7.6G of oracle memory inside 6G of allocation.

my guess is you are seeing ORA-00845 errors because of this.

So, make /dev/shm larger or your memory_max_target lower
0
 

Author Comment

by:carlino70
Comment Utility
I'm not seeing errors like ORA-00845 in AlertLog
But if the base, shows slow queries and runs Oracle jobs.
Thanks
0
 

Author Comment

by:carlino70
Comment Utility
sorry, I wrote bad:
But the database, shows slow queries and runs Oracle jobs.
0
PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

 
LVL 73

Accepted Solution

by:
sdstuber earned 500 total points
Comment Utility
The instance shouldn't start if you have memory_target (or max_memory_target) of 7.6G with only 6G of shared memory.

Maybe I misunderstood what you posted above, are all of those code boxes suggestions or are some of them what you currently have?

I thought the 8G change was the suggestion and the rest was what you actually had, in which case I would expect an error.


If all of it is a suggestion, then yes, go with that.  It should work.
0
 

Author Closing Comment

by:carlino70
Comment Utility
Excellent!, Thanks
0
 
LVL 73

Expert Comment

by:sdstuber
Comment Utility
Glad I could help.

Making sure your shared memory at the OS level is big enough for the instance's memory is just an extension of the same thing you would have had to do when the database was created.

Configuring /dev/shm to be big enough is one of the preinstallation requirements

http://docs.oracle.com/cd/E11882_01/install.112/e47689/pre_install.htm#LADBI1096

Here you're already installed, but if you're making your instance bigger, then same idea as the preinstall.  You must also make the /dev/shm big enough to hold it.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Join & Write a Comment

Article by: Swadhin
From the Oracle SQL Reference (http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/queries006.htm) we are told that a join is a query that combines rows from two or more tables, views, or materialized views. This article provides a glimps…
Cursors in Oracle: A cursor is used to process individual rows returned by database system for a query. In oracle every SQL statement executed by the oracle server has a private area. This area contains information about the SQL statement and the…
This video explains at a high level about the four available data types in Oracle and how dates can be manipulated by the user to get data into and out of the database.
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…

772 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

Need Help in Real-Time?

Connect with top rated Experts

10 Experts available now in Live!

Get 1:1 Help Now