MEMORY_MAX_TARGET recommendations. Automatic memory management AMM

Posted on 2012-08-14
Last Modified: 2012-08-22
I am looking at increasing the memory in our databases.
select name, value, display_value from v$parameter
where name like '%sga%'
select name, value, display_value from v$parameter
where name like '%memory%';

Open in new window

I want to go to automatic memory management and increase the memory_max_target to 6G.     Inorder to do this I need to increase the tmpfs to greater then 6G. The default is 50% of memory.
tmpfs                   /dev/shm                tmpfs   defaults        0 0

I read I can do the following.
To adjust the shared memory file system size issue the following commands, specifying the required size of shared memory.

# umount tmpfs
# mount -t tmpfs shmfs -o size=6144m /dev/shm
Make the setting permanent by amending the "tmpfs" setting of the "/etc/fstab" file to look like this.

tmpfs                   /dev/shm                tmpfs   size=6144m      0 0

[root@x ~]# df ls -la /dev/shm
df: `ls': No such file or directory
Filesystem           1K-blocks      Used Available Use% Mounted on
tmpfs                  4194304   2208512   1985792  53% /dev/shm
[root@reptstdwhdb01 ~]# df ls -h /dev/shm
df: `ls': No such file or directory
Filesystem            Size  Used Avail Use% Mounted on
tmpfs                 4.0G  2.2G  1.9G  53% /dev/shm
[root@x ~]# 

Open in new window

My questions are is there any standards for setting automatic memory.
I know I have 8G memory I want to assign 6G to memory_max_target
I know if I don't assign more then 6G to tmpfs I will get an error.
I read on
that the tmpfs should be 20% more then memory_max_target.

I could drop memory_max_target to 5G approx or increase tmpfs to approx 7G.  I need some guidance. Thanks in advance.
Question by:dplinnane
    1 Comment
    LVL 76

    Accepted Solution

    >>My questions are is there any standards for setting automatic memory.

    No real standards that I know of.  You just never want to swap memory to disk.  As long as 2 Gig will support all the server processes you will ever have then 6 Gig should be fine.

    >>df ls -la /dev/shm

    df and ls are stand-alone commands.

    Instead of a Blog I would suggest the installation guide from oracle.

    Oracle® Database Installation Guide
     11g Release 2 (11.2) for Linux

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    Find Ransomware Secrets With All-Source Analysis

    Ransomware has become a major concern for organizations; its prevalence has grown due to past successes achieved by threat actors. While each ransomware variant is different, we’ve seen some common tactics and trends used among the authors of the malware.

    SSH (Secure Shell) - Tips and Tricks As you all know SSH(Secure Shell) is a network protocol, which we use to access/transfer files securely between two networked devices. SSH was actually designed as a replacement for insecure protocols that sen…
    Background In several of the companies I have worked for, I noticed that corporate reporting is off loaded from the production database and done mainly on a clone database which needs to be kept up to date daily by various means, be it a logical…
    This video shows how to copy a database user from one database to another user DBMS_METADATA.  It also shows how to copy a user's permissions and discusses password hash differences between Oracle 10g and 11g.
    This video shows setup options and the basic steps and syntax for duplicating (cloning) a database from one instance to another. Examples are given for duplicating to the same machine and to different machines

    737 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

    22 Experts available now in Live!

    Get 1:1 Help Now