Bug: /def/shm does not use /etc/fstab attributes after reboot

SOLVED: this issue is solved in Linux 6.4 (kernel: 2.6.39-400.17.1.el6uek and 2.6.32-358.el6).
A single entry in /etc/fstab like [tmpfs /dev/shm tmpfs size=3g 0 0] now works as it should!

There is a bug in Red Hat Linux 6 and Oracle Enterprise Linux 6 (UEK and RHEL-kernel) and probably all other Red Hat 6 related Linux Distro’s.

When you need more memory for SGA/PGA when using MEMORY_MAX_TARGET, you need to resize /dev/shm. By default this is 50% of total memory and Oracle tells you to add the following to /etc/fstab, ‘mounting’ the /dev/shm twice (?):

shmfs /dev/shm tmpfs size=3g 0 0

Which works… Continue reading

Oracle Linux 6, oracle-validated is missing? no renamed!

In Oracle Linux 6, it looks like the ‘oracle-validated’ package is missing, but Oracle actually renamed it to ‘oracle-rdbms-server-11gR2-preinstall.x86_64‘.

To quickly use the public yum repository of Oracle and install ‘oracle-rdbms-server-11gR2-preinstall.x86_64’:

cd /etc/yum.repos.d
wget http://public-yum.oracle.com/public-yum-ol6.repo
#vi /etc/yum.repos.d/public-yum-ol6.repo
yum clean all
yum repolist
yum install oracle-rdbms-server-11gR2-preinstall.x86_64

You will get the ‘latest’ build enabled.
If you don’t want this, vi /etc/yum.repos.d/public-yum-ol6.repo .

Happy installing!

Get wget command for a Metalink / My Oracle Support download with FireFox cliget add-on

Today I ran into an add-on for FireFox which can create a wget command from a download file dialog box. First thing that came in mind was; Will this work for Metalink / My Oracle Support? Yes is does!

The add-on is called ‘cliget’ and can be downloaded here: cliget add-on for FireFox. Continue reading

Public yum package ‘oracle-validated’ problems on 64bit OEL

I was preparing some fresh installed OEL5.5 machines for database software installation, but after running ‘yum install oracle-validated‘, the OUI did not pass the prerequisites on two packages. It seems it did not install unixODBC-devel x86_64 and libaio-devel x86_64.

Their Linux may be unbreakable, but their ‘oracle-validated’ package on the public yum server seemed to be broken. Continue reading

Theoretical problem when WebLogic’s NodeManager is using a start script

Many people will use the WebLogic’s NodeManager to use the start script for starting Managed Servers:

StartScriptEnabled=true

The NodeManager will start the Managed Server using the script and monitor the Managed Server when it fails.

One of the mistakes people can make is creating their own start script and start the Managed Server using ‘nohup &’ within this script: Metalink [ID 984122.1] and [ID 861098.1]. The script will finish and the server keeps running, but the NodeManager thinks the Managed Server has failed… Continue reading

Oracle 11g AMM: MEMORY_TARGET, MEMORY_MAX_TARGET and /dev/shm

I knew in Oracle 11g with Automatic Memory Management (AMM), the database was able to give unused memory back to the OS, controlled by MEMORY_TARGET and MEMORY_MAX_TARGET.

This mechanism is present in 11g since day 1 (in 2007), but I never actually played with it.

MEMORY_TARGET and MEMORY_MAX_TARGET

The Oracle documents state the following:

MEMORY_TARGET specifies the Oracle system-wide usable memory.
MEMORY_MAX_TARGET (…) decide on a maximum amount of memory that you would want to allocate to the database for the foreseeable future.

So my guess is, MEMORY_MAX_TARGET (static) is the maximum you can set MEMORY_TARGET (dynamic) to. A couple of days ago, I wanted to experiment a bit with these memory settings.

Continue reading

Temporary stop listener to log with ‘set log_status’

When moving/deleting the listener.log, I used to stop and start the listener and move/delete the listener in between the actions.
This method has a big inconvenience: users can not connect to the database for a few seconds…
What I never knew was that the listener could be told to stop and start logging and take the appropriate action in between. Continue reading

Xming: wrong authentication protocol

Ever had the “wrong authentication protocol” error when using Xming and xhost+ still did not work?

When you are on a private network, you can try using the “-ac” option when starting Xming. Use this only on private trusted networks, because it gives access to everyone.

For mote information on Access Control in Xming and X-Forwarding with PuTTY and SSH, check the Xming troubleshoot guide.

Happy consulting!