Andreas' Adventures

Today I decided to abandon Oracle VM and move back to VMWare. A while ago I bought my old 4GB laptop from my company, when I was given a new one. I added a 1TB disk and installed Oracle VM 2.2 on it. There are some quirks with Oracle VM when it comes to support low end systems. First of all the system is memory bound quite fast. See an earlier post of me (http://achatzia.blogspot.com/2010/05/oracle-vm-memory-issue.html) to see how Oracle VM treats it memory. The second main issue is the problem with external USB2.0 devices. I ended up rebooting an image quite often as the SCSI drive was declared dead. I worked with VMWare since about 6 years, and only had lost one image - a colleague disconnected my external drive which resulted in a corrupt Oracle database. With Oracle VM I never had that stability. So for me it is good-bye OVM, and welcome back VMWare Server. Obviously the VMWare Server will run on a Linux host with Oracle Enterprise Linux 5.5 .

I was reinstalling my Oracle VM (again). During the configuration of the Oracle VM Manager template I ran into an error: OVM-2007. The template (new OVM image) could not find the host it was running on. Quick check in the /etc/hosts file of the OVM Server showed: 127.0.0.1 ovm.mydomain.local ovm localhost.localdomain localhost So I changed it to read: 127.0.0.1 localhost.localdomain localhost 10.1.1.100 ovm.mydomain.local ovm localhost.localdomain localhost To me as a Unix veteran it is still a mistery why somebody came up with the idea to put anything besides 127.0.0.1 localhost into the first line.

Recently I had a lot of disk errors on my Oracle VM server. The errors indicated that some scsi problems were manifesting itself with: unable to enumerate USB device on port 2 After unloading and reloading the ehci_hcd it seems to be gone.

After some first baby steps with Oracle VM I wanted to push this thing a little bit further. So my idea was to have more than a couple of VM's running simultaneously. The Oracle VM told me however that I had not enough memory to do this. So I was sitting in front of my dedicated laptop and told the screen that there should be 4 GB inside. The laptop however had one of his funny days and told me (using free and top) that really nothing more than 572 MB would be inside the machine. Hmm - when a machine tells me something I am the first to listen. So I shutdown everything, got my screwdriver, opened the memory compartment and had a look. Indeed 1 bank of 2GB. I didn't check the second bank as this is hidden underneath the keyboard. Closing the machine and powering it up, I prepared myself for another round of telling it that it should recognize a little bit more than 572 MB. I examined the dmesg and still it told me that there was only 572 MB inside. Now imagine, you have just see...

Just for your convenience: When you start an Oracle VM image from the commandline with xm create -c ./vm.cfg you will see that the boot process continues until the login is displayed: EXT3-fs: mounted filesystem with ordered data mode. type=1403 audit(1272761495.554:2): policy loaded auid=4294967295 ses=4294967295 Enterprise Linux Enterprise Linux Server release 5.4 (Carthage) Kernel 2.6.18-164.0.0.0.1.el5xen on an i686 soa.mydomain.local login: In order to get back to your commandline type CTRL-] and you will get back the control.

I have just added three submisions for OOW 2010. Automate the creation of extra Coherence machines based on Grid Control data Use Oracle VM to learn Oracle technology Build a Coherence cluster using Oracle VM to speed up Oracle FMW

One size does not fit all. The Oracle VM template comes with just the twm windows manager. Since my days in University I dislike this thing. For me it is Motif. So in order to get my favorite Windows manager up and running I need to install it. Luckily Oracle offers a public yum server. Do the following: cd /etc/yum.repos.d wget http://public-yum.oracle.com/public-yum-el5.repo Edit this file and set the stanza to enabled for the corresponding entry. The template is based on EL5 Update4. Then just run yum install openmotif Afterwards I modify the xstart file in the /home/oracle/.vnc directory to use mwm instead of twm. In order to access the vncviewer I also need to modify the iptables. Add a line into the iptables to enable access in the port range 5900-5950. This will enable the access of the custom vncserver, as well as the vncserver which runs on the VM Server. The second vncserver acts as a console for the VM image. Depending on the order in which the VM's are started the vnc p...

I could change the hostname of the VM template for the WebCenter. This would be done on the OS using the standard Linux way (change /etc/hosts, /etc/sysconfig/network). However as the Oracle Application Server OC4J is still configured with the template hostname (haovm007) I would need to changethis. Now - as a lot of you know - the hostname and domainname change in the OC4J is not the easiest tasks of the Application Server Administration. So I decided to build a WebCenter machine from scratch. A) It is easier B) I learn all the steps (probably have to install it more than once) C) I configure it as I would like to have it D) It is more fun

The beauty of the Oracle VM templates is of course the ease with which you create a new machine. But then it has to work, or at least it must be customizable. I have created a new machine from a WebCenter VM template. During the boot it asks for the network configuration. This seems to work, as ifconfig returns the correct settings. However the machinename is not used. I entered webcenter1 but the template still has the haovm007: While I am a Bond fan I'd rather see my own name for the machine. Let's see how this can be corrected.

I thought it worked - but of course I forgot the Oracle VM Manager on my second machine. It still displayed the ServerPool1 that I had created previously. In order to begin with a clean slate you might need to drop the database in the Oracle VM Server. Login to the server as root and execute the following commands: service stop ovs-agent rm -rf /etc/ovs-agent/db service start ovs-agent Then the external disk needs to be added again: [root@ovm utils]# ./repos.py --new /dev/sdb1 [ NEW ] 6ad759c5-d706-4b3a-9d14-bcffafc61fc3 => /dev/sdb1 [root@ovm utils]# ./repos.py --list [ ] 6ad759c5-d706-4b3a-9d14-bcffafc61fc3 => /dev/sdb1 [root@ovm utils]# ./repos.py --root 6ad759c5-d706-4b3a-9d14-bcffafc61fc3 [ R ] 6ad759c5-d706-4b3a-9d14-bcffafc61fc3 => /dev/sdb1 The filesystems were back again and also the directories in /OVS. Now back to importing a VM Template.

I rebuild my OVM server for the n-th time this morning. Problem was that it was difficult to have the external disk mounted on the /OVS directory. I tried to add a shared virtual disk - which I formatted as an ocfs2 disk to the existing disk. I found this excellent posting http://geertdepaep.wordpress.com/2008/06/09/oracle-vm-and-multiple-local-disks/ that described the process and guided me into the correct direction. Although the disk was visible in the repos.py script I was unable to see it in the Oracle VM Manager. Now I thought that I need to build the server and format the filesystems myself. Sorry I have no screenshots here as the installer runs on the machine itself. During the installation the two disks (internal 50 GB and external 1 TB) are shown as /dev/sda and /dev/sdb. In the disk setup utility in the installer choose the option to define a custom layout. The installer offers a predefined layout, which it would normally apply to the available disks. I decided to have three...

Although my Oracle VM Manager was running on OEL, I reinstalled the machine with Fedora and obviously I wanted the OVM Manager back on it. The installation was pretty straight forward. Two tiny things had to be done in order to convince the installer to proceed. I needed to comment out the checks for the OS and the libaio package. After this the installer was on its way. During the Oracle XE installation I adapted the swapfile (created a big additional swapfile) as the XE installer decided to stop when tere was not enough swap space. Conclusion: OVM Manager runs fine on Fedora.

Added a 1 TB disk to my OVM machine :-) [root@ovm ~]# mkfs -t ext3 /dev/sdb mke2fs 1.39 (29-May-2006) /dev/sdb is entire device, not just one partition! Proceed anyway? (y,n) y Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 122109952 inodes, 244190646 blocks 12209532 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=0 7453 block groups 32768 blocks per group, 32768 fragments per group 16384 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 38 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@ovm ~]# So - now the fun...