Posts made in December, 2008

Oracle and Architecture

Posted by dan on Dec 15, 2008 in Computers, Oracle | 3 comments

After a morning searching the internet wondering what possibly could be the issue with Oracle clusterware not linking it became apparent i’d made a huge mistake.

Can you spot it ..

[root@Oracle1 orainstall]# uname -a

Linux Oracle1 2.6.18-92.el5xen #1 SMP Fri May 23 23:49:15 EDT 2008 x86_64 x86_64 x86_64 GNU/Linux

[root@Oracle1 orainstall]# ls

10201_clusterware_linux32.zip

GUTTED not what i needed right now

Posted by dan on Dec 14, 2008 in Computers | 3 comments

Mortified, you can’t see completely but three are lit up

More Oracle woes…

Posted by dan on Dec 14, 2008 in Computers, Oracle | 2 comments

Copyright (C) 1999, 2005, Oracle. All rights reserved.

Exception java.lang.UnsatisfiedLinkError: /tmp/OraInstall2008-12-14_02-30-18PM/jre/1.4.2/lib/i386/libawt.so: libXp.so.6: cannot open shared object file: No such file or directory occurred..

Oracle Installation woes…

Posted by dan on Dec 13, 2008 in Computers, Linux, Oracle | 0 comments

Oracle installs normally require a long time to change various settings and this is before you can get to the barebones install. A quick step through the ‘basics’ of setting up oracle requires:

- Tuning of Kernel Network parameters

- Creation of Users/groups

- Creation of Oracle directories/correct permissions

- Checking Physical memory/swap

- Configuration of Shared memory segments (more kernel tuning)

- Configuration of Semaphores (Read here (if you care))

- Configuration of File Handles

- Configuration of IP port ranges

- Configuration of various shell contraints

This is before you’ve installed one piece of Oracle software, and can result in some tedious work. I’ve created ‘albeit a rough edition’ a script that should hopefully reduce this tedium to about 2-3 minutes work. It’s only for linux EL at the moment, however it’ll be tuned to work on Solaris as soon as I build another host and tune the script.  Few to-do’s and i’ll upload it, perhaps someone might use it.

Removing a Persistent Bridge in xen after reboots

Posted by dan on Dec 5, 2008 in virtualization, Xen | 0 comments

The most common method for networking using xen is to use a network bridge with your physical ethernet and then the virtual nics associated with xen domains. The default install and configuration will result in a default xen bridge (xenbr0) which will have your ethernet and virtual nics in. This information has to be explicitly declared in the various xen configuration files, however xen will take care of the actual plumbing and configuring of the bridge and the interfaces. 

However, xen has an oddity (in my opinion) it appears that xend will monitor the bridges on your dom0 and add any other bridges to it’s state. Which means should you manually create a bridge e.g. 

spike ~ # brctl addbr testbr0

xend will see that this bridge has been created and add it to it’s state configuration. On a reboot or restart of xend, what will happen is that xend will configure the networking back to the state that it recorded. This means that not only will xenbr0 be created so will testbr0, which wouldn’t be a problem if your virtual nics were added to the correct bridge (xenbr0). However they more than likely be added to testbr0 meaning that your domU’s will have no networking, unless you manually move the virtual nic to the correct bridge. 

To permanently remove bridges you need to stop xend (/etc/init.d/xend stop *BEWARE* this will stop all domUs) then go to /var/lib/xend/state/ and edit the network.xml. The entire network uuid section containing the bridge you want removing will need deleting, ensure you back everything up before hand. 

Starting xend now will result in only the correct bridges being created and the domUs nics will be added to the correct bridge.