Increasing number of allocated file handles

Lee Higginbotham lee.higginbotham at pic.com
Wed Oct 4 18:35:49 UTC 2006


Dominique,

I'm by far, no Oracle Guru, but I seem to remember there was a static
number of handles within Oracle.  And it seems to me that we had to
change our licensing.  But that is completely from memory.

That was Oracle 9i running on a HP-UX 11 HP 9000 L Class Server

Sincerely,
Lee Higginbotham
Senior IT Technical Analyst
100 Bluegrass Commons Blvd., Suite 2200
Hendersonville, TN  37075
Ph:  615-265-2764
Fax:  615-265-2847
lee.higginbotham at pic.com
-----Original Message-----
From: redhat-sysadmin-list-bounces at redhat.com
[mailto:redhat-sysadmin-list-bounces at redhat.com] On Behalf Of Art
Wildman
Sent: Wednesday, October 04, 2006 1:32 PM
To: redhat-sysadmin-list at redhat.com
Subject: Re: Increasing number of allocated file handles

Dominique Demore wrote:
> Hi Everyone,
>
> On our Oracle Application server, we have noticed that we are running
out of file handles. Once the number of used file
> handles reaches 0, the application crashes/reset itself.
> I have increased the number of file handles from 65536 to 104854, but
I am still seeing the problem. Should the number
> of allocated file handles be increase also, if so, where is the file
to modify it.
>
> (*note: the second column will hit 0 everyday at ~9:00 when everyone
is logging into the system.)
> ------
> [root at server fs]# cat /proc/sys/fs/file-nr 
> 39937   7405    104854
> [root at server fs]# 
> -------
>
>
> Any thoughts/suggestions,
>
>   

Tuning and Optimizing RHEL for Oracle 9i and 10g Databases (Red Hat 
Enterprise Linux, 4, 3, 2.1 - redhat, x86-64)
http://www.puschitz.com/TuningLinuxForOracle.shtml#SettingFileHandles
...The maximum number of file handles can be changed in the proc file 
system without reboot:

# echo 65536 > /proc/sys/fs/file-max

Alternatively, you can use sysctl(8) to change it:

# sysctl -w fs.file-max=65536

To make the change permanent, add or change the following line in the 
file /etc/sysctl.conf. This file is used during the boot process.

# echo "fs.file-max=65536" >> /etc/sysctl.conf

-------------------

Short Guide to install Oracle 10g on Gentoo Linux (2004.0)
http://www.akadia.com/services/ora_linux_install_10g.html

...Setting Shell Limits for the Oracle User
   Most shells like Bash provide control over various resources like the

maximum allowable number of open file descriptors or the maximum number 
of processes available to a user.

    To see all shell limits, run:

    $ ulimit -a

Setting Limits for the Maximum Number of Open File Descriptors for the 
Oracle User

    After you changed and increased /proc/sys/fs/file-max (see: Checking

Kernel Parameters), there is still a per user limit of open file 
descriptors which is set to 1024 by default:

    $ su - oracle
    $ ulimit -n
    1024

    To change this, you have to edit the file /etc/security/limits.conf 
as root and make the following changes or add the following lines, 
respectively:

    # To increase the shell limits for Oracle 10.1.0
    oracle soft nproc 2047
    oracle hard nproc 16384
    oracle soft nofile 1024
    oracle hard nofile 65536

    The <soft limit> in the first line defines the number of file 
handles or open files that the Oracle user will have after login. If the

Oracle user gets error messages about running out of file handles, then 
the Oracle user can increase the number of file handles like in this 
example up to 63536 (<hard limit>) by running the following command:

    ulimit -n 63536

    Note that we do not recommend to set the <hard limit> for nofile for

the oracle user equal to /proc/sys/fs/file-max. If you do that and the 
user uses up all the file handles, then the system would run out of file

handles. This could mean that you won't be able to initiate new remote 
logins any more since the system won't be able to open any PAM modules 
which are required for performing a login. That's why we set the hard 
limit to 63536 and not to 65536.

    You also need to make sure that pam_limits is configured in the file

/etc/pam.d/system-auth. This is the PAM module that will read the 
/etc/security/limits.conf file. The entry should read like:

    session required /lib/security/pam_limits.so
    session required /lib/security/pam_unix.so

    Now login to the oracle account again since the changes will become 
effective for new login sessions only.
-------------------

File System Primer - Novell CoolSolutionsWiki
http://wiki.novell.com/index.php/File_System_Primer


EXT3

    * Most popular Linux file system, limited scalability in size and
      number of files
    * Journaled
    * POSIX extended access control

EXT3 file system is a journaled file system that has the greatest use in

Linux today. It is the "Linux" File system. It is quite robust and 
quick, although it does not scale well to large volumes nor a great 
number of files. Recently a scalability feature was added called htrees,

which significantly improved EXT3's scalability. However it is still not

as scalable as some of the other file systems listed even with htrees. 
It scales similar to NTFS with htrees. Without htrees, EXT3 does not 
handle more than about 5,000 files in a directory.

-HTH
--
Art Wildman
National Weather Service Office, JAX FL. http://www.srh.noaa.gov/jax
"If you choose not to decide, you still have made a choice"
-Rush|Freewill

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