Mount ocfs2 image on ubuntu

I received an oracle file system image that i need to access in order to recover from backup files. So i needed to enable ocfs2 support on linux.

First, install support packages:

sudo apt-get install ocfs2-tools ocfs2console ocfs2-tools-dev

Next, you must mount the file to a loopback device, so it can be used like a disk.

sudo losetup /dev/loop0 ocfs2_dump.img

You can now run the oracle file system console

sudo ocfs2console

Your loopback device should be now visible.
Go to the menu cluster, configure nodes, and add a new node. The name should be your hostname and the ip address can be

sudo /etc/init.d/o2cb load
sudo /etc/init.d/o2cb online

Now you can use the ocfs2 console interface to mount your image.

Run mysqldump without lock

Extracting a dump from a brig production mysql database may be troubling, because it causes the tables in the database to lock and any service can become offline.

But the mysqldump command have a lock tables switch that can prevent the tables to lock.

Just add


to the dump command.

All new files in folder writable by all users in group

I need to make sure that all users in a group have read/write access to all files in a shared folder, old and new files.

First, make sure that all existing files and folders are in the group

chgrp group . -R

And all new files and folders must be in the same group too

chmod g+s . -R

Finally, the files created by all users must have read/write permissions to the group. We must ensure what this command is run whenever a user logs on system.

umask 002

We can ensure that by adding this line to /etc/bashrc.


Could not create the Java virtual machine.

I have a brand new VPS on, that runs on overvz.

My OS is Linux Ubuntu 12.04 and i needed to install tomcat-solr. By running

sudo apt-get install ca-certificates-java


I was getting the error:

Could not create the Java virtual machine.

By following this link i found that oracle java7 works perfectly on Ubuntu over openvz.

All I needed to do was:

  • Remove openjdk
sudo apt-get purge openjdk*

  • Add the repository
sudo add-apt-repository ppa:eugenesan/java
sudo apt-get update

  • Install java7 sdk
sudo apt-get install oracle-java7-installer

  •  Now the tomcat-solr will work as excpected
sudo apt-get install tomcat-solr


Hope it works, good luck to your new server :)